drm046, low power bldc drive for fans using the ... · low power bldc designer reference reference...

MOTOROLA.COM/SEMICONDUCTORS

M68HC08Microcontrollers

DRM046Rev. 0, 09/2003

Low Power BLDC

Designer Reference

Reference Design

Manual

Drive for Fans usingthe MC68HC908QY4

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Freescale Semiconductor, Inc.

For More Information On This Product, Go to: www.freescale.com

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DRM046 — Rev 0 Designer Reference Manual

MOTOROLA 3

Low Power BLDC Drive for Fans using the MC68HC908QY4 Reference DesignDesigner Reference Manual — Rev 0

by: Radim Visinka, MCSL, Roznov

BLDC Motor Theory by: Pavel Grasblum, MCSL, Roznov

Metrowerks and the Metrowerks logo are registered trademarks of Metrowerks, Inc., a wholly owned subsidiary of Motorola, Inc.

CodeWarrior is a registered trademark of Metrowerks, Inc., a wholly owned subsidiary of Motorola, Inc.

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Designer Reference Manual DRM046 — Rev 0

4 MOTOROLA

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MOTOROLA List of Sections 5

Designer Reference Manual — DRM046

List of Sections

Section 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Section 2. MC68HC908QY Family Advantages and Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Section 3. BLDC Motor Theory . . . . . . . . . . . . . . . . . . . . 17

Section 4. 3-Phase BLDC Low Voltage Reference Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Section 5. Hardware Design. . . . . . . . . . . . . . . . . . . . . . . 31

Section 6. Software Design . . . . . . . . . . . . . . . . . . . . . . . 45

Section 7. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Section 8. Appendix A — Schematics and Parts List . .63

Section 9. Appendix B — System Set-up . . . . . . . . . . . . 71

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List of Sections


6 List of Sections MOTOROLA

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MOTOROLA Table of Contents 7


Table of Contents

Section 1. Introduction

Section 2. MC68HC908QY Family Advantages and Features

Section 3. BLDC Motor Theory

3.1 Digital Control of a BLDC Motor . . . . . . . . . . . . . . . . . . . . . . . .18

3.2 Independent Switching of Power Transistors . . . . . . . . . . . . . .19

3.3 Complementary Switching of Power Transistors . . . . . . . . . . .20

3.4 Commutation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Section 4. 3-Phase BLDC Low Voltage Reference Design

4.1 Application Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

4.2 Application Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

Section 5. Hardware Design

5.1 Pin-by-Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

5.2 Detailed Design Description . . . . . . . . . . . . . . . . . . . . . . . . . . .36

Section 6. Software Design

6.1 Data Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45

6.2 Software Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49

6.3 Application Porting for the Customer Specific BLDC Motor . . .52

6.4 Software Listing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57

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Table of Contents


8 Table of Contents MOTOROLA

6.5 Microcontroller Memory and Peripheral Usage . . . . . . . . . . . .58

Section 7. References

Section 8. Appendix A — Schematics and Parts List

8.1 Schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63

8.2 Parts Lists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67

Section 9. Appendix B — System Set-up

9.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71

9.2 Hardware Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71

9.3 Jumper Settings for Controller Board . . . . . . . . . . . . . . . . . . . .72

9.4 Required Software Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74

9.5 Building and Uploading the Application . . . . . . . . . . . . . . . . . .74

9.6 Executing the Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75

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MOTOROLA List of Figures 9


List of Figures

Figure Title Page

1-1 Low Power BLDC Drive for Fan . . . . . . . . . . . . . . . . . . . . . . . .133-1 BLDC Motor - Cross Section . . . . . . . . . . . . . . . . . . . . . . . . . .173-2 Voltage Strokes Applied to the 3-ph BLDC Motor . . . . . . . . . .183-3 3-phase BLDC Power Stage. . . . . . . . . . . . . . . . . . . . . . . . . . .193-4 Independent Switching of Power Transistors . . . . . . . . . . . . . .203-5 Complementary Switching of Power Transistors . . . . . . . . . . .213-6 Stator Flux Vectors at Six-Step Control . . . . . . . . . . . . . . . . . .223-7 Situation Right Before Commutation . . . . . . . . . . . . . . . . . . . .233-8 Situation Right After Commutation . . . . . . . . . . . . . . . . . . . . . .234-1 System Concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .275-1 Three-Phase BLDC Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . .325-2 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .335-3 Microcontroller with Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . .385-4 Hall Sensor Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .395-5 User’s Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .405-6 3-Phase H Bridge (Phase A Shown) . . . . . . . . . . . . . . . . . . . .425-7 Current Sensing - Detail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .436-1 Algorithm Data Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .466-2 Closed Loop Speed Control . . . . . . . . . . . . . . . . . . . . . . . . . . .486-3 Software Implementation - General Overview . . . . . . . . . . . . .506-4 Stator Flux Vectors with Sectors. . . . . . . . . . . . . . . . . . . . . . . .538-1 Microcontroller with Hall Sensor Input and User’s Interface . . .648-2 Power Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .658-3 Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .669-1 Setup of the Application with BLDC Motor . . . . . . . . . . . . . . . .729-2 Jumper Reference of BLDC Drive Board . . . . . . . . . . . . . . . . .73

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List of Figures


10 List of Figures MOTOROLA

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MOTOROLA List of Tables 11


List of Tables

Table Title Page

2-1 Summary of Device Variations . . . . . . . . . . . . . . . . . . . . . . . . .153-1 Commutation Sequence for Counterclockwise Rotation . . . . .243-2 Commutation Sequence for Clockwise Rotation . . . . . . . . . . .245-1 Connector J4 Signal Descriptions. . . . . . . . . . . . . . . . . . . . . . .345-2 Jack Connector J2 Signal Descriptions . . . . . . . . . . . . . . . . . .345-3 Connector J5 Signal Descriptions. . . . . . . . . . . . . . . . . . . . . . .345-4 Jack Connector J1 Signal Descriptions . . . . . . . . . . . . . . . . . .355-5 Jack Connector J3 Signal Descriptions . . . . . . . . . . . . . . . . . .365-6 Connection of Signals to MCU . . . . . . . . . . . . . . . . . . . . . . . . .376-1 Determination of Hall Sensor Pattern . . . . . . . . . . . . . . . . . . . .536-2 Determination of Commutation Vector for CCW. . . . . . . . . . . .546-3 Determination of Commutation Vector for CW . . . . . . . . . . . . .556-4 Commutation Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .566-5 Memory Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .586-6 MC68HC908QY4 Modules Usage . . . . . . . . . . . . . . . . . . . . . .588-1 Parts List. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .679-1 BLDC Drive Board Jumper Settings . . . . . . . . . . . . . . . . . . . . .73

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List of Tables


12 List of Tables MOTOROLA

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MOTOROLA Introduction 13


Section 1. Introduction

This Application Note describes the design of a low power 3-phase BLDC (Brushless DC) motor drive with Hall Sensors, based on Motorola’s MC68HC908QY4 microcontroller.

Figure 1-1. Low Power BLDC Drive for Fan

BLDC motors are very popular in a wide application area. Compared with a DC motor, the BLDC motor uses an electric commutator (replacing the mechanical commutator), and so is more reliable than the DC motor. In BLDC motors, rotor magnets generate the rotor’s magnetic flux so that they achieve higher efficiency. Therefore, BLDC motors may be used in white goods, high-end pumps, fans and in other appliances which require high reliability and efficiency.

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Introduction


14 Introduction MOTOROLA

The concept of the application is a speed-closed loop BLDC drive using a Hall position sensor. It serves as a reference design of a BLDC motor control system for a low voltage fan application. The power stage is designed for 48V DC line voltage and 400W output power. The application is based on the low-cost MC68HC908QY4 “Nitron“ microcontroller. The design is focused on minimal cost and maximal component integration for low cost applications.

This Application Note includes the basic motor theory, system design concept, hardware and software design, hardware schematics, and s/w listing. The design can be used as a reference design for developing customer specific applications.

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MOTOROLA MC68HC908QY Family Advantages and Features 15


Section 2. MC68HC908QY Family Advantages and Features

The MC68HC908QY4 is a member of the low-cost, high-performance M68HC08 Family of 8-bit microcontroller units (MCUs). All MCUs in the family use the enhanced M68HC08 central processor unit (CPU08) and are available with a variety of modules, memory sizes and types, and package types.

Features include:

• High-performance M68HC08 CPU core

• 5-V and 3-V operating voltages (VDD)

• 8-MHz internal bus operation at 5 V, 4-MHz at 3 V

• Trimmable internal oscillator

– 3.2 MHz internal bus operation

– 8-bit trim capability (± 25% untrimmed, ± 5% trimmed)

• Auto wake-up from STOP capability

Table 2-1. Summary of Device Variations

Device FLASH Memory Size RAM Memory SizeAnalog-to-Digital

ConverterPin

Count

MC68HC908QT1 1536 bytes 128 Bytes - 8 pins

MC68HC908QT2 1536 bytes 128 Bytes 4 ch, 8 bit 8 pins

MC68HC908QT4 4096 bytes 128 Bytes 4 ch, 8 bit 8 pins

MC68HC908QY1 1536 bytes 128 Bytes - 16 pins

MC68HC908QY2 1536 bytes 128 Bytes 4 ch, 8 bit 16 pins

MC68HC908QY4 4096 bytes 128 Bytes 4 ch, 8 bit 16 pins

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MC68HC908QY Family Advantages and Features


16 MC68HC908QY Family Advantages and Features MOTOROLA

• On-chip in-application programmable FLASH memory

• On-chip random-access memory (RAM)

• • 2-channel, 16-bit timer interface module (TIM)

• • 4-channel, 8-bit analog-to-digital converter (ADC) on MC68HC908QY2, MC68HC908QY4, MC68HC908QT2, and MC68HC908QT4

• 5 or 13 bidirectional input/output (I/O) lines, and one input only

• 6-bit keyboard interrupt with walk-up feature (KBI)

• Low-voltage inhibit (LVI) module

• System protection features

• External asynchronous interrupt pin with internal pull-up (IRQ) shared with general-purpose input pin

• Master asynchronous reset pin (RST) shared with general-purpose input/output (I/O) pin

• Power-on reset

• Power saving stop and wait modes

• MC68HC908QY4, MC68HC908QY2, and MC68HC908QY1 are available in these packages:

– 16-pin plastic dual in-line package (PDIP)

– 16-pin small outline integrated circuit (SOIC) package

– 16-pin thin shrink small outline package (TSSOP)

• • MC68HC908QT4, MC68HC908QT2, and MC68HC908QT1 are available in these packages:

– 8-pin PDIP

– 8-pin SOIC

– 8-pin dual flat no lead (DFN) package

The BLDC motor control application requires six PWM outputs, three Hall position sensor inputs and an ADC channel for voltage measurements as a minimum. Therefore 16-pin MC68HC908QY2 or MC68HC908QY4, that accommodate ADC, are the right choice.

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MOTOROLA BLDC Motor Theory 17


Section 3. BLDC Motor Theory

A brushless DC (BLDC) motor is a rotating electric machine where the stator is a classic three-phase stator like that of an induction motor, and the rotor has surface-mounted permanent magnets (see Figure 3-1. BLDC Motor - Cross Section).

In this respect, the BLDC motor is equivalent to a reversed DC commutator motor, in which the magnet rotates while the conductors remain stationary. In the DC commutator motor, the current polarity is altered by the commutator and brushes. On the other hand, in the brushless DC motor, the polarity reversal is performed by power transistors switching in synchronization with the rotor position. Therefore, BLDC motors often incorporate either internal or external position sensors to sense the actual rotor position, or the position can be detected without sensors.

Figure 3-1. BLDC Motor - Cross Section

Stator

Stator winding(in slots)

Shaft

Rotor

Air gap

Permanent magnets

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BLDC Motor Theory


18 BLDC Motor Theory MOTOROLA

3.1 Digital Control of a BLDC Motor

The BLDC motor is driven by rectangular voltage strokes coupled with the given rotor position (see Figure 3-2. Voltage Strokes Applied to the 3-ph BLDC Motor). The generated stator flux interacts with the rotor flux, which is generated by a rotor magnet, defines the torque and thus the speed of the motor. The voltage strokes must be properly applied to the two phases of the three-phase winding system so that the angle between the stator flux and the rotor flux is kept close to 90°, to get the maximum generated torque. Due to this fact, the motor requires electronic control for proper operation.

Figure 3-2. Voltage Strokes Applied to the 3-ph BLDC Motor

For the common 3-phase BLDC motor a standard 3-phase power stage is used, as is illustrated in Figure 3-3. 3-phase BLDC Power Stage. The power stage utilizes six power transistors with switching in either the independent mode or complementary mode.

30º 60º 90º 120º 150º 180º 210º 240º 270º 300º 330º Electricalangle

Voltage

Phase A

Phase B

Phase C

+UDCB

-UDCB

+UDCB

-UDCB

+UDCB

-UDCB

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BLDC Motor TheoryIndependent Switching of Power Transistors



Figure 3-3. 3-phase BLDC Power Stage

In both modes the 3-phase power stage energizes two motor phases concurrently. The third phase is unpowered (see Figure 3-2. Voltage Strokes Applied to the 3-ph BLDC Motor). Thus, we get six possible voltage vectors that are applied to the BLDC motor using a PWM technique. There are two basic types of power transistor switching: independent switching, and complementary switching.

3.2 Independent Switching of Power Transistors

With independent switching, only two transistors are switched on when current is conducted from the power supply to the phase of the BLDC motor. In one phase, the top transistor is switched on; in the second phase, the bottom transistor is switched on and the third phase is not powered. During freewheeling all transistors are switched off (see Figure 3-4. Independent Switching of Power Transistors).

Q1

PWM_Q5

Q6Q4

C1

Phase_C

PWM_Q1

PWM_Q4

PWM_Q3

Phase_BGND

Q2

UDCB

PWM_Q2

Phase_A

Q3

PWM_Q6

Q5

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BLDC Motor Theory



Figure 3-4. Independent Switching of Power Transistors

3.3 Complementary Switching of Power Transistors

With complementary switching, two transistors are switched on when the phase of the BLDC motor is connected to the power supply. But there is a difference during freewheeling. With independent switching, all the transistors are switched off. The current continues to flow in the same direction through freewheeling diodes until it falls to zero. Contrary to this, with complementary switching, the complementary transistors are switched on during freewheeling. Thus the current may be able to flow in the opposite direction. Figure 3-5. Complementary Switching of Power Transistors depicts the complementary switching.

10º 20º 30º 40º 50º 60º 70º 80º 90º Electricalangle

PWM Q1

PWM Q2

PWM Q3

PWM Q4

PWM Q5

PWM Q6

PWMswitching

ON

OFFON

OFF

OFF

ON

ON

OFF

OFF

OFF

ON

ON

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BLDC Motor TheoryCommutation



.

Figure 3-5. Complementary Switching of Power Transistors

3.4 Commutation

Commutation provides the creation of a rotation field. As was explained, for the proper operation of a BLDC motor it is necessary to keep the angle between the stator and rotor flux close to 90°. With six-step control we get a total of six possible stator flux vectors. The stator flux vector must be changed at a certain rotor position. The rotor position is usually sensed by Hall sensors. The Hall sensors generate three signals that also comprise six states. Each of the Hall sensors’ states corresponds to a certain stator flux vector. All of the Hall sensor states with corresponding stator flux vectors are illustrated in Figure 3-6. Stator Flux Vectors at Six-Step Control. The same figure is illustrated in tables Table 3-1. Commutation Sequence for Counterclockwise Rotation and Table 3-2. Commutation Sequence for Clockwise Rotation.

10º 20º 30º 40º 50º 60º 70º 80º 90º Electricalangle

PWM Q1

PWM Q2

PWM Q3

PWM Q4

PWM Q5

PWM Q6

PWMswitching

ON

OFFON

OFF

OFF

ON

ON

OFF

OFF

OFF

ON

ON

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BLDC Motor Theory



Figure 3-6. Stator Flux Vectors at Six-Step Control

The next two figures depict the commutation process. The actual rotor position in Figure 3-7. Situation Right Before Commutation corresponds to the Hall sensors’ state ABC[011] (see Figure 3-6. Stator Flux Vectors at Six-Step Control). The actual voltage pattern can be derived from Table 3-1. Commutation Sequence for Counterclockwise Rotation. Phase A is connected to the positive DC-Bus voltage by the transistor Q1; phase C is connected to the ground by transistor Q6, and phase B is unpowered.

As soon as the rotor reaches a certain position (see Figure 3-7. Situation Right Before Commutation) the Hall sensors’ state changes its value from ABC[011] to ABC[010]. From Table 3-1. Commutation Sequence for Counterclockwise Rotation a new voltage pattern is selected and applied to the BLDC motor.

As can be seen, using a six-step control technique, there is no possibility of keeping the angle between the rotor flux and the stator flux precisely at 90°. The real angle varies from 60° to 120°.

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BLDC Motor TheoryCommutation



The commutation is repeated per each 60 electrical degrees. The commutation event is critical for its angular (time) accuracy. Any deviation causes the torque ripples and hence speed variation.

Figure 3-7. Situation Right Before Commutation

Figure 3-8. Situation Right After Commutation

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BLDC Motor Theory



Table 3-1. Commutation Sequence for Counterclockwise Rotation

Hall Sensor A Hall Sensor B Hall Sensor C Phase A Phase B Phase C

1 0 1 +VDCB -VDCB NC

1 0 0 +VDCB NC -VDCB

1 1 0 NC +VDCB -VDCB

0 1 0 -VDCB +VDCB NC

0 1 1 -VDCB NC +VDCB

0 0 1 NC -VDCB +VDCB

Table 3-2. Commutation Sequence for Clockwise Rotation

Hall Sensor A Hall Sensor B Hall Sensor C Phase A Phase B Phase C

1 0 1 -VDCB +VDCB NC

0 0 1 NC +VDCB -VDCB

0 1 1 +VDCB NC -VDCB

0 1 0 +VDCB -VDCB NC

1 1 0 NC -VDCB +VDCB

1 0 0 -VDCB NC +VDCB

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MOTOROLA 3-Phase BLDC Low Voltage Reference Design 25


Section 4. 3-Phase BLDC Low Voltage Reference Design

4.1 Application Outline

The system is designed to drive a 3-phase BLDC motor. The reference design meets the following performance specification:

• Voltage control of BLDC motor using Hall sensors

• Single board solution with MC68HC908QY2/4 “Nitron“ microcontroller

• Power supply voltage +48VDC (range form +36VDC to +56VDC)

• Maximal power 200W (power devices rated for 100V/57A)

• Control technique incorporates:

– Position sensing using Hall sensor signals

– Voltage BLDC motor control with speed-closed loop

– Speed measurement based on Hall Sensors

– One direction of rotation

– Motoring/Generator mode

– Start from any motor position without rotor alignment

– Pre-charging of MOSFET pre-driver bootstraps before each motor start

– Minimal speed 750 RPM (according to the motor used)

– Maximal speed 4000 RPM (according to the motor used)

• Manual interface (run/stop switch, speed potentiometer, power-on LED indication)

• Option to connect user’s interface through terminals

• Fault protection:

– DC-Bus over-current fault protection (hardware/software)

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3-Phase BLDC Low Voltage Reference Design


26 3-Phase BLDC Low Voltage Reference Design MOTOROLA

– DC-Bus under-voltage fault protection (software)

– DC-Bus over-voltage fault protection (software)

– Loss of Hall sensors (software)

• Power Supply Accommodation

– Fuse on power line input

– Transient Voltage Suppressor 60 Volts

– Line choke (limited to 8 Amps)

4.2 Application Description

The drive is illustrated in Figure 4-1. System Concept. The system incorporates:

• Single Board BLDC Drive with MC68HC908QY4 “Nitron“ microcontroller

• BLDC Motor with Hall sensors

The MCU MC68HC908QY4 runs the main control algorithm. According to the user interface and feedback signals it generates 3-phase PWM output signals for a 3-phase inverter.

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3-Phase BLDC Low Voltage Reference DesignApplication Description



Figure 4-1. System Concept

4.2.1 Six-Channel PWM Generation

Six output pins of MC68HC908QY4 are used for control of power MOSFETs. Since the MC68HC908QY4 accommodates just one timer with two timer channels, a general purpose I/O pins needs to be used for the gate signal generation. They are two possibilities of PWM generation using the general purpose I/O pins:

• Use s/w PWM generation on GPIO

• Use external logic with PWM generation using timer of MCU

The first option enables to generate arbitrary PWMs on individual pins. The output compare and overflow ISRs of the on-chip timer can serve as a reference event for the output pin toggle to get the desired PWM pulses. The outputs are controlled purely by s/w. The advantage is the simplicity of the hardware where individual pins are connected directly to

PWMGeneration

SpeedCommand

MC68HC908QY4

Fault Protection

SpeedRamp

Duty Cycle

SpeedProcessing

(Input capture)

SpeedPI

Contr.

-

+

Motor Speed

SpeedError BLDC

State Machine

Commutation Vector

Hall SensorSignals

C

12VDC

5VDC

=

3-phBLDC

48VdcHS

Drivers=

PWM'sDC

-Bus

Vol

tage Gate PWM

FilterCap

NAND Logic

StartStop

SpeedSetup

User Interface

DC-Bus Current

Over-Current Fault

B

A

PWM

PWMGeneration

SpeedCommand

MC68HC908QY4

Fault Protection

SpeedRamp

Duty Cycle

SpeedProcessing

(Input capture)

SpeedPI

Contr.

-

+

Motor Speed

SpeedError BLDC

State Machine

Commutation Vector

Hall SensorSignals

C

12VDC

5VDC

=

3-phBLDC

48VdcHS

Drivers=

PWM'sDC

-Bus

Vol

tage Gate PWM

FilterCap

NAND Logic

StartStop

SpeedSetup

User Interface

DC-Bus Current

Over-Current Fault

B

A

PWM

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3-phase gate driver. The key disadvantages are the considerable fluctuation of PWM duty cycle due to the software interrupt service and interrupts latency; difficulties in getting PWM duty cycles close to 0 and 100% boundaries, due to the necessary software execution, and last but not least, the MCU overloading due to the frequent highest priority PWM interrupts at each PWM edge. As a result the technique has just a limited use.

The second option gives more precise output control signals with the disadvantage of more complex hardware. The PWM is generated by the on-chip timer output compare function, and the general purpose pins serve just to deliver the PWM to the respective input of 3-phase gate driver. Such topology enables controlling the power stage and the BLDC motor in independent unipolar mode, while the same PWM is always present on one top and one bottom switch of two different phases. The other power switches are turned off. The advantages are stable PWM signals, possibility of generating duty cycles from 0 to 100%, and off-loading the MCU. The draw-back is the increased hardware complexity. This topology has been selected for the reference design of BLDC drive.

4.2.2 Control Algorithm Description

The state of the user interface is periodically scanned, while the speed of the motor is measured on each new coming edge from the Hall sensors (only one phase is used for speed measurement). According to the state of the control signals (run/stop switch, speed pot) the speed command is calculated. The acceleration/deceleration ramp is implemented. The comparison between the actual speed command and the measured speed generates a speed error. This speed error is input to the speed PI controller, that generates a new corrected PWM duty cycle.

The Hall sensor signals are scanned independently on a speed control loop. According to the Hall sensor signals the proper commutation vector is selected and applied to the MCU output pins.

The PWM duty cycle value, together with commutation vector, defines the PWM control signals for the BLDC power stage. The PWM is

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3-Phase BLDC Low Voltage Reference DesignApplication Description



generated by the output compare function on the timer pin, while 6 GPIO pins are set/cleared according to the commutation vector. Six external NAND logic gates provide PWM signals to the MOSFET pre-drivers according to the generated PWM (see Figure 5-3. Microcontroller with Logic).

The bootstrap capacitors of high-side MOSFET drivers require pre-charging before the motor is started. Therefore, all three low-side MOSFETs are turned on for 10msec before each motor start. Such operation enables charging the bootstrap capacitors and a reliable motor start up.

4.2.3 Protection Features

During deceleration the motor can work as a generator. In the generator state, the DC-Bus capacitor is charged and its voltage can easily exceed its maximal voltage. Therefore, the DC-Bus voltage is measured and compared with the limit. Where there is deceleration over-voltage, the deceleration is interrupted and the motor runs with constant speed in order to discharge the DC-Bus capacitor. Then deceleration can continue.

The drive accommodates a fault protection. DC-Bus current is evaluated by hardware and in the case of an over-current, a fault signal is generated. The fault signal is processed by MCU interrupt (IRQ) and software immediately disables the PWM output. DC-Bus voltage is measured during the control process. Where there is over-voltage or under-voltage, the drive enters a fault state. If any of the afore mentioned faults occur, the motor control PWM outputs are disabled in order to protect the drive. The drive can be enabled again using the run/stop switch.

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MOTOROLA Hardware Design 31


Section 5. Hardware Design

The 3-phase BLDC drive is DC 48 volt, 200 watt single board drive controlled by MC68HC908QY4 microcontroller. It provides a ready-to-use reference design as well as a ready-made software development platform for fractional horsepower BLDC motors. Feedback signals from Hall sensors, a typical position sensor used in BLDC motor applications, are provided, - allowing 3-phase BLDC motors to be controlled in closed speed loop.

An illustration of the drive is shown in Figure 5-2. Block Diagram.

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Hardware Design


32 Hardware Design MOTOROLA

Figure 5-1. Three-Phase BLDC Drive

The drive features are:

• on-board microcontroller MC68HC908QY4 with output control logic circuitry

• 3-phase Hall sensor inputs with pull-ups and filters

• Selectable 5VDC and 12VDC available on Hall sensor terminal

• DC input 48VDC with range form +36VDC to +56VDC accommodating:

– Fuse on power line input

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Hardware DesignPin-by-Pin Descriptions



– Transient Voltage Suppressor 60 Volts

– Line choke limited to 8 Amps

• 3-phase MOSFETs gate pre-driver IR2132

• 3-phase bridge inverter (6-MOSFETs 100V/57A)

• DC-Bus current sensing shunt for DC-Bus over-current detection

• DC-Bus over-current fault generation circuitry set to 10 Amps threshold on DC-Bus

• low-voltage on-board power supplies 5V/200mA and 12V/400mA with power-on LED indication

• manual control interface (speed pot, run/stop switch)

• Terminals for optional external user interface

Figure 5-2. Block Diagram shows a system architecture of the drive.

Figure 5-2. Block Diagram

5.1 Pin-by-Pin Descriptions

Inputs and outputs are located on five connectors. Pin descriptions for each of these connectors are included in this section.

48V Input

User Interface

Power Input

Interface

3-Ph. MosFET Inverter

Power Supply

3-Ph. Gate Drivers with Over-Current

Detection

MCU "Nitron"

3-phaseMotor

Output

3-phaseHall Sensor

InputsFilter

J2J4 J5

J1J3

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Hardware Design



5.1.1 Power Input Connectors J4 and J2

The power input connector, labelled J4, is located on the front edge of the board. It will accept dc voltages from 36 to 56 Volts. It is extremely important to connect the power supply in correct polarity as described in Table 5-1. Connector J4 Signal Descriptions.

For demo purposes, the power supply jack connector J2 is added.

5.1.2 Motor Output Connector

Power outputs to the motor are located on connector J5. Phase outputs are labelled Phase_A, Phase_B, and Phase_C. Pin assignments are described in Table 5-3. Connector J5 Signal Descriptions.

Table 5-1. Connector J4 Signal Descriptions

Pin No. Signal Name Description

1 GND Power supply ground

2 +48VDC Power Supply positive rail 48VDC

Table 5-2. Jack Connector J2 Signal Descriptions


1 (centre) +48VDC Power Supply positive rail 48VDC





1 Phase_A Phase_A supplies power to motor phase A.

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Hardware DesignPin-by-Pin Descriptions



5.1.3 Hall Sensor Input

Inputs of the Hall sensor are located on connector J1. Pin assignments are described in Table 5-4. Jack Connector J1 Signal Descriptions. The power supply level for the Hall sensor can be selected as +12VDC or +5VDC using the 0Ω resistors R41 or R42.

WARNING: Never solder both resistors R41 and R42 at the same time - it will cause a short circuit between 5VDC and +12VDC rails.

5.1.4 User Interface Selector

The user interface consists of a speed potentiometer and run/stop switch. Both signals are connected with the MCU through jumpers. If desired, the on-board interface may be disconnected and the external

2 Phase_B Phase_B supplies power to motor phase B.

3 Phase_C Phase_C supplies power to motor phase C.





1 GND Ground

2 HS_A Hall sensor - Phase A

3 HS_B Hall sensor - Phase B

4 HS_C Hall sensor - Phase C

5 HS_PowerPower supply for Hall sensors- if R41 soldered: HS_Power = +12VDC- if R42 soldered: HS_Power = +5VDC

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Hardware Design



user interface used, connected to the header J3. Pin assignments are described in Table 5-5. Jack Connector J3 Signal Descriptions.

5.2 Detailed Design Description

Circuit descriptions for the 3-phase BLDC drive appear in this chapter. Microcontroller with output logic sensing is discussed in 5.2.1 Microcontroller with Logic. Hall senor interface is highlighted in 5.2.2 Hall Sensor Interface. The user’s interface and Bootloader interface is shown in 5.2.3 User’s Interface and Bootloader. One phase leg of the 3-phase H-bridge is looked at in 5.2.5 3-Phase H Bridge. DC-Bus over-current feedback is discussed in 5.2.6 Current Sensing. Finally, on-board power supply appears in 5.2.7 Power Supply.

5.2.1 Microcontroller with Logic

The microcontroller is the brain of the application. It evaluates the user interface signals, Hall sensor signals, and DC-Bus voltage, generating six signals for 3-phase H-bridge. The topology is shown in Figure 5-3. Microcontroller with Logic.

The individual interface signals are wired to the MCU as shown in Table 5-6. Connection of Signals to MCU.



1 Speed Pot Analog speed reference 0-5V

2 Run/Stop Switch Run enable

3 PTA4 Port A pin 4 configured as ADC2

4 PTA3 Port A pin 3 configured as GPIO

5 +5VDC +5VDC power supply

6 GND ground

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Hardware DesignDetailed Design Description



As can be seen, all signals of MC68HC908QY4 are used.

Six outputs, PTB0-PTB5 are used for control of the power MOSFETs. They are wired through NAND’s with open collector and corresponding pull-ups. The PWM is generated on TCH0, and the individual pins PTB0 - PTB5 enable the PWM to appear at the corresponding input of the 3-phase gate driver.

When power is applied or removed, it is important that the top and bottom output transistors in the same phase are not turned on simultaneously. Since logic states are not always defined during power-up, it is important to ensure that all power transistors remain off when the controller’s supply voltage is below its normal operating level. Since the inputs of the 3-phase gate driver IR2132 have negative logic, the pull-up resistors R35-R40 disable the driver outputs. Also, pull down

Table 5-6. Connection of Signals to MCU

Signal MC6+8HC908QY4 Pins

Hall Sensor A PTB7

Hall Sensor B PTB6

Hall Sensor C PTA1 / TCH1

Phase A Top PTB0

Phase A Bottom PTB1

Phase B Top PTB2

Phase A Bottom PTB3

Phase C Top PTB4

Phase C Bottom PTB5

PWM / Enable PTA0 / TCH0

Fault Input PTA2 / IRQ

DC-Bus Voltage PTA5 / AD3

Speed Pot PTA4 / AD2

Run / Stop Switch PTA3

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Hardware Design



resistor R28 ensures the save state on the NAND logic during power-on, when MCU pins are configured as high impedance inputs. This feature ensures that all power transistors remain off during power-up and power-down.

Figure 5-3. Microcontroller with Logic

5.2.2 Hall Sensor Interface

The Hall sensor interface circuitry provides filtered Hall sensor signal for the microcontroller. The pull-ups on all 3 phase signals are implemented. The configuration resistors R41 and R42 enable selecting the appropriate voltage of +12VDC or +5VDC on pin 5 of the J1 connector, using zero-ohms resistors. WARNING: Never populate both resistors

R3510k

R3610k

R3710k

R3810k

R3910k

R4010k +5V

PB0 PWM_ATPB1 PWM_ABPB2 PWM_BTPB3 PWM_BBPB4 PWM_CTPB5 PWM_CB

HallSensor_AHallSensor_B

HallSensor_C

Speed Pot

Run/Stop Switch

+5V

GND

U5C

MC74HC03AD

9

108

U5B

MC74HC03AD

4

56

U5D

MC74HC03AD

12

1311

U5A

MC74HC03AD

1

23

U6B

MC74HC03AD

4

56

U6C

MC74HC03AD

9

108

V_DCBUS

PWM_AT

PWM_BT

PWM_CB

PWM_BB

PWM_CTR2810k

GND

Fault

U1

MC68HC908QY4SOIC

Vdd1

PTB72

PTB63

PTA5/OSC1/AD3/KBI54

PTA4/OSC2/AD2/KBI45

PTB56

PTA3/*RST/KBI38 PTB47

PTA2/IRQ/KBI2 9PTB3 10PTB2 11PTA1/AD1/TCH1/KBI1 12PTA0/AD0/TCH0/KBI0 13PTB1 14PTB0 15Vss 16

PWM_AB

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R41 and R42! This causes a short circuit between +12VDC and +5VDCrails.

For brushless motors that use Hall sensor inputs for commutation, noise immunity of the sensor inputs is a key design consideration. Noise on these inputs can be particularly troublesome, since commutation to the wrong state precludes smooth operation of the motor. To facilitate noise, the sensor inputs are filtered with 1000-nsec single-pole filters, as shown in Figure 5-4. Hall Sensor Interface. Using relatively low value pull-up resistors, in the order of 1 kΩ., provides an additional measure of noise immunity.

Figure 5-4. Hall Sensor Interface

5.2.3 User’s Interface and Bootloader

The user interface enables controlling the drive. It is shown in Figure 5-5. User’s Interface. The speed can be set-up using a potentiometer, - connected through a jumper to channel AD2 of the ADC. A small ceramic capacitor C16 is inserted for signal filtering. The run/stop switch

+12V

GND

GND

+5V

R11k

+5V

R21k

R51k

+5V

+C12u2/20V

C2100nF

C54n7

C64n7

C74n7

R3 220R

R4 220R

R6 220R

GND+5V

R41 0R

R42 0R

J1

12345

HS_A

HS_CHS_B

Hall SensorsConnector

PTA1

PTB6

PTB7

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Hardware Design



is connected to Port PTA3 also through a jumper. The jumpers enable connection of an external user interface to MCU pins PTA3 and PTA4/AD2 if desired. Please be aware that maximal applicable voltage to both MCU pins is +5Vdc.

The pin PTA4 serves for programming the Flash using Flash bootloader. After Reset, the bootloader attempts to communicate through selected pin (PTA3). If there is a response from the programmer, the Flash can be programmed through this pin. If there is no response, after a defined time-out the user’s program is entered. When using the serial bootloder, the ceramic capacitor C16 should be removed.

Figure 5-5. User’s Interface

5.2.4 Power Line Input with DC-Bus Voltage Sensing

Main power supply needs to be connected to power supply terminal. The schematics are shown in Figure 8-2. Power Stage. A fuse F1 is used for short circuit protection. An input capacitor C17 and open former suppression choke L1 provides power supply filtering. The choke is rated for 8 Amps. Unipolar transient voltage suppressor D5 protects against power supply voltage peaks higher than 60V.

Feedback signal proportional to DC-Bus voltage is provided for the microcontroller. DC-Bus voltage is scaled down by a voltage divider

R501k

J3

Header

246

135

GND

P15k

+5V

GND

+5V GNDSW1RUN/STOP

21

3

PTA3

PTA4 / AD2

C1610nF

GND

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consisting of R11 and R12. The values are chosen such that a 65-volt maximum DC-Bus voltage corresponds to 5 volts at output V_DCBUS.

5.2.5 3-Phase H Bridge

The output stage is configured as a 3-phase H-bridge with IGBT output transistors. It is simplified considerably by a high-voltage integrated 3-phase gate driver that has a cycle-by-cycle current limit feature with over-current detection and fault generation. A schematic that shows one phase is illustrated in Figure 5-6. 3-Phase H Bridge (Phase A Shown).

Gate drive is supplied by an International Rectifier, IR2132. It is a high voltage, high speed power MOSFET and IGBT driver with three independent high and low side referenced output channels. Under-voltage lockout and over-current protection are also provided by the IR2132.

One of the more important design decisions in a motor drive is the selection of gate drive impedance for the output transistors. In Figure 5-6. 3-Phase H Bridge (Phase A Shown), resistor R16, resistor R30, diode D8, and the IR2132’s current source/sinking capability determine gate drive impedance for the lower half-bridge transistor. A similar network is used on the upper half-bridge. These networks set turn-on gate drive impedance at approximately 24 ohms and turn-off gate impedance to approximately 4 ohms. These values produce transition times of approximately 200 nsec.

The gate of the MOSFETs is protected by 18V Zener diodes D18 and D21 that eliminate possible dangerous peaks on the gate signals. Discharge resistors R44 and R47 are placed in parallel.

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Hardware Design



Figure 5-6. 3-Phase H Bridge (Phase A Shown)

5.2.6 Current Sensing

As mentioned, the 3-phase driver IR2132 contains cycle-by-cycle current limit feature with over-current detection and fault generation. An on-chip ground-referenced operational amplifier provides analog feedback of bridge current via an external current sense resistor. A current trip function, which terminates all six outputs is also derived from this resistor. An open drain /FAULT signal indicates if an over-current or under-voltage shutdown has occurred.

Figure 5-7. Current Sensing - Detail illustrates the detailed topology of the circuitry derived from Figure 5-6. 3-Phase H Bridge (Phase A Shown). Both operational amplifier and comparator are available within IR2132, so just resistors R21 and R22 are needed externally. The resistors R21 and R22 define the gain of the on-chip operational amplifier. The gain is set to -10. The over-current trip is set internally to 0.5V. It corresponds to 10A for DC-Bus sensing resistor 0.005 ohms and

Motor Ph A

GND

Phase COutput

Phase BOutput

Phase C Input

Phase B Input

R430R C36

GND

+12V

C21470nF/25V

C25100nF

R1524R

R1624R

Fault

+12V

Optional filter

GND

+12V

D7MURS160T3

+

C24100uF/25V

C35100nF

DC Bus cureentsensing resistors

U2

IR2132S

HIN23

LIN26

HIN34

LIN37

HIN12

LIN15

FAULT8

ITRIP9

CA010

CA-11

VCC1

VSS12

VS1 26HO1 27VB1 28

LO1 16

LO2 15

LO3 14

HO2 23

HO3 19

VB2 24

VB3 20

VS2 22

VS3 18

VS013

D6MBRS240LT3

D8MBRS240LT3

PWM_ATPWM_AB

R2182k - 1%

R228k2 - 1%

GND

R294R7

R304R7

0.5V @ (Imax=10A)

R140R010 - SBL4

R130R010 - SBL4

D18MMSZ5248BT1

R4447k

D21MMSZ5248BT1

R4747k

Q1IRF3710

+48V

Q4IRF3710

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gain -10. The optional filter (C36/R43) at the output of the operational amplifier, helps to filter undesirable noise. If not used, 0 ohms resistor R43 will be inserted.

Where there is over-current, all six gate driver outputs are disabled, and a fault is generated. Since the generated fault signal is an open collector output, the internal pull-up of MC68HC908QY4 is utilized.

Figure 5-7. Current Sensing - Detail

5.2.7 Power Supply

On-board power supply provides auxiliary +5Vdc and +12Vdc. The topology is shown in Figure 8-3. Power Supply. The input voltage (in range from +36Vdc to +56Vdc) is decreased to +12V by a switched mode DC-DC converter LT1676. It accepts input voltage up to +60Vdc. The +12Vdc is used for supplying the 3-phase gate driver and optionally for supplying of the Hall position sensor. The +12Vdc power supply is rated to 400mA.

The +12Vdc is further decreased by linear regulator MC78M05 giving +5Vdc. The +5Vdc is used for supplying the microcontroller, user

R230R

GND

C37

Optional filterR2182k - 1%

R228k2 - 1%

GND

+

-

Amplifier

+

-

Comparator

+0.5V

R140R010 - SBL4

R130R010 - SBL4

GND

power groundtrack of thepower stage

0.5V @(Imax=10A)

Fault

IR2132

ITRIP

CA-CAO

/FAULT

VC0

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Hardware Design



interface, logic, and optionally, the Hall position sensors. The +5Vdc power supply is rated to 400mA.

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MOTOROLA Software Design 45


Section 6. Software Design

This section describes the design of the software blocks of the drive. The software will be described in terms of -

• Control Algorithm Data Flow

• Software Implementation

• Software Listing

• Microcontroller Memory and Peripheral Usage

6.1 Data Flow

The requirements of the drive dictate that software takes some values from the user interface and sensors, processes them and generates 3-phase PWM signals for motor control.

The control algorithm of closed loop BLDC drive is described in Figure 6-1. Algorithm Data Flow. It consists of processes described in following sub-sections.

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Software Design


46 Software Design MOTOROLA

Figure 6-1. Algorithm Data Flow

6.1.1 Speed Command and ADC Measurement

The input parameters of the process - run/stop switch and speed potentiometer are evaluated and the speed command, ucOmegaReq, is

Speed Commandand ADC Measurement

Sensor Handler

ucSensorVectorucSensorVector

ucVoltageDCBucVoltageDCB ucOmegaRequcOmegaReq

Hall Sensors A, B, C(Port)

Run/Stop Switch(Port)

Speed Pot(ADC)

DC Bus Voltage(ADC)

Acceleration Ramp

uiOmegaReqRampuiOmegaReqRamp

Commutation&

PWM Generation

PTBPTB

TCH0TCH0

Speed PI Controller

uiDutyCycleOutuiDutyCycleOut

uiOmegaActualuiOmegaActual

Fault Protection

Fault(IRQ)

PTBPTB

Output Gate Signals Generation

Output Gate Signals Clearing

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Software DesignData Flow



calculated accordingly. Also the DC bus voltage, ucVoltageDCB, is measured.

6.1.2 Sensor Handler

The application utilizes 3-phase Hall position sensor for control algorithm. It is used for both commutation vector generation and for the actual speed calculation.

For the calculation of the commutation vector, all three Hall sensor inputs are evaluated. A three-bit commutation pattern, ucSensorVector, is created. It is later used for selection of proper commutation pattern in process Commutation & PWM Generation.

The speed measurement utilizes the IC function of the timer. It reads the time between consequential rising edges of the selected phase of Hall sensor output, and calculates the actual motor speed, uiOmegaActual. Also, a software filter of the speed measurement may be incorporated into the process for better noise immunity. In this case the actual motor speed is calculated as an average value of several measurements.

6.1.3 Acceleration Ramp

The process calculates the new speed command, uiOmegaReqRamp, based on the required speed, ucOmegaReq, according to the acceleration ramp.

During deceleration the motor can work as a generator. In the generator state the DC-Bus capacitor is charged and its voltage can easily exceed its maximal voltage. Therefore the DC-Bus voltage is measured and compared with the limit. In the case of deceleration over-voltage, the deceleration is interrupted and the motor runs with constant speed in order to discharge the capacitor. Then deceleration can continue.

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Software Design



6.1.4 Speed Controller

The speed closed loop control is characterized by the measurement of the actual motor speed. This information is compared with the reference set point and the error signal is generated. The magnitude and polarity of the error signal corresponds to the difference between the actual and required speed.

The speed PI controller generates the corrected output duty cycle in order to compensate for the error. The general principle of the voltage control loop is illustrated in Figure 6-2. Closed Loop Speed Control.

Figure 6-2. Closed Loop Speed Control

6.1.5 Commutation & PWM Generation

The commutation process generates the proper commutation pattern on six gate signals outputs, while the PWM generation process generates the appropriate PWM signal for the selected gate outputs. The commutation pattern is selected from commutation table using the three-bit commutation vector, ucSensorVector. This pattern is then loaded into the selected outputs of Port B of the microcontroller. The PWM is generated by the on-chip timer using the output compare (OC) function, according to the required output duty cycle, uiDutyCycleOut. The PWM is generated on timer output of the microcontroller. Then the on-board logic is used for selection of the PWM to the 3-phase gate driver.

PIController

ControlledSystem

SpeedError

ReferenceSpeed

Corrected Speed

(uiDutyCycleOut)(uiOmegaReqRamp)

Actual MotorSpeed

(uiOmegaActual)

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Software DesignSoftware Implementation



6.1.6 Fault Protection

This process is responsible for fault handling. The software accommodates two fault inputs: DC-Bus over-current signal and DC-Bus voltage measurement.

DC-Bus over-current is detected by on-board hardware circuitry. In the case of an over-current, the external hardware provides a falling edge on the /IRQ input of the microcontroller. This signal invokes a non-masked interrupt with highest priority. The interrupt service routine puts all PWM gate signals into a non-active safe state, and sets the fault status of the drive.

DC-Bus voltage is used for software under-voltage and over-voltage protection. The sensed DC-Bus voltage is compared with the limit within the software. In the case of a detected fault, the service routine puts all PWM gate signals into a non-active safe state, and sets the fault status of the drive.

If any of the faults occurs the service routine puts the drive into a safe fault state that does not enable the drive operation. It can be left by turning the run/stop switch to the stop position.

6.2 Software Implementation

The general software implementation is illustrated in Figure 6-3. Software Implementation - General Overview. It incorporates the main routine entered from Reset and three interrupt states. The Main Routine includes the initialization of the microcontroller and the application, and a Software Timer for the control algorithm time base. The interrupt states provides calculation of actual speed of the motor, fault handler and PWM generation process with motor commutation.

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Software Design



Figure 6-3. Software Implementation - General Overview

6.2.1 Initialization

The Main Routine provides initialization of the microcontroller:

• initializes MCU core

– enables IRQ interrupt, enable IRQ pull-up

• COP and LVI enable (CONFIG register)

• disable KeyBoard interrupts

• sets-up I/O ports

OverFlow Interrupt of Timer 0

Over-flowInterrupt Handler

Input Capture Interrupt of Timer 1

Input CaptureInterrupt Handler done

done

MCU & ApplicationInitialization

SoftwareTimer Timeout

RESET

Timeout

done

IRQ Interrupt

FaultInterrupt Handler

done

done

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Software DesignSoftware Implementation



• initializes Timer 0 for Output Compare (OC)

• initializes Timer 1 for Input Capture (IC)

• initializes Analog to Digital Converter

The MCU has just one 16-bit timer counter with two timer channels. The counter is primarily used for the generation of PWM signal of desired period. The duty cycle is defined by timer channel 0 set as an output compare. Channel 1 is used for the speed measurements using the input capture function. It measures the time between the edges of the Hall sensor signal.

After MCU initialization application, variables are initialized and the interrupts are enabled.

6.2.2 Interrupts

The interrupt handlers provide the following services:

• OverFlow Interrupt Handler is used for update of PWM duty cycle and determination of the commutation vector based on the Hall sensor signals (Process Commutation and PWM generation).

• Input Capture (IC) Interrupt Handler reads the time between the two consequential IC edges (basic part of the Process Speed Sensor). Since the only timer of the MCU is used for PWM generation, the determination of time between the Hall sensor edges is based on the number of PWM periods.

• Fault Interrupt Handler takes care of over-current fault interrupt (over-current part of the Process Fault Control)

6.2.3 Software Timer

The software timer routine provides the timing sequence for required subroutines running in the background. The background routine is called in 10msec time-out. The timing is based on counting of the PWM periods.

The background routine provides:

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Software Design



• Service of Analog-to-Digital Converter for DC-Bus voltage and speed pot measurements

• Determination of desired speed based on application state machine (Stop, Charging, Run, Fault)

• Calculation of the speed command based on speed ramp with DC-Bus over-voltage protection during deceleration

• Calculation of the desired duty cycle using speed PI controller.

6.3 Application Porting for the Customer Specific BLDC Motor

The definition of the correct commutation table is the key point of the application porting for the customer specific BLDC motor. The aim of the process is the definition of the commutation pattern that is generated at the MCU ports according to the sensed Hall sensor pattern. The process of definition has the following steps:

1. Determination of Hall sensor pattern for each commutation sector

2. Determination of commutation vector for each Hall sensor pattern

3. Determination of commutation table according to the s/w implementation

6.3.1 Determination of Hall Sensor Pattern

First, the Hall sensor pattern corresponding to the BLDC motor sector needs to be determined. The determination can be done by supplying all three phases, by combination of positive and negative voltage, that cause the motor to move to the given sector, and observing the Hall sensor signals when the motor settles. Table 6-1. illustrates the required phases to be powered for the desired sector and the example of sensor output for the given BLDC motor. The sectors I - VI correspond with the sectors shown in Figure 6-4. Stator Flux Vectors with Sectors.

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Software DesignApplication Porting for the Customer Specific BLDC Motor



Figure 6-4. Stator Flux Vectors with Sectors

6.3.2 Determination of Commutation Vector

When the Hall sensor patterns are defined, the corresponding commutation vectors shall be determined. For each sector I-VI, the corresponding commutation vector A-F and Hall sensor pattern is

Table 6-1. Determination of Hall Sensor Pattern

Sector Powered Phases Sensor Output of the Motor

Phase A Phase B Phase C Hall A Hall B Hall C

I -U -U +U 1 0 1

II -U +U +U 0 0 1

III -U +U -U 0 1 1

IV +U +U -U 0 1 0

V +U -U -U 1 1 0

VI +U -U +U 1 0 0

II

III

VI V VI

I

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Software Design



defined. Table 6-2. Determination of Commutation Vector for CCW shows the vectors for counterclockwise direction of rotation that ensures the variation of real angle from 60° to 120° (see chapter 3.4 Commutation). The Hall sensor pattern, considered as a binary number, results in a decimal number from 1 to 6 (e.g. 101 in binary form corresponds to decimal number 5). From Table 6-2. Determination of Commutation Vector for CCW we can see that commutation vector A corresponds to decimal Hall sensor pattern 5, commutation vector B to number 1, etc.

In the case of clockwise direction of rotation, the commutation vector can be determined using the Table 6-3. Determination of Commutation Vector for CW.

Table 6-2. Determination of Commutation Vector for CCW

Sector Commutation VectorVector

Determined Hall Sensor Pattern HS Pattern ResultPhase A Phase B Phase C HS A HS B HS C

I -VDCB +VDCB NC A 1 0 1 5

II NC +VDCB -VDCB B 0 0 1 1

III +VDCB NC -VDCB C 0 1 1 3

IV +VDCB -VDCB NC D 0 1 0 2

V NC -VDCB +VDCB E 1 1 0 6

VI -VDCB NC +VDCB F 1 0 0 4

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Software DesignApplication Porting for the Customer Specific BLDC Motor



6.3.3 Determination of Commutation Table

In the application software, the commutation vectors are defined in a table of 8 values (entry 0-7). Any Hall sensor pattern gives the right pointer to the table of commutation vectors. For our example, the commutation table shown in Table 6-4. Commutation Table shall be used. Please note that Hall sensor pattern 0 [000] and 7 [111] indicates a fault, since such a combination is not available during normal operation. Such a state can be caused, e.g. by a disconnected Hall sensor interface, or it’s malfunction. In that case, the output channels are switched off (output signals are put into a safe state) in order to protect the drive.

Table 6-3. Determination of Commutation Vector for CW

Sector Commutation VectorVector

Determined Hall Sensor Pattern HS Pattern ResultPhase A Phase B Phase C HS A HS B HS C

I +VDCB -VDCB NC D 1 0 1 5

II +VDCB NC -VDCB C 1 0 0 4

III NC +VDCB -VDCB B 1 1 0 6

IV -VDCB +VDCB NC A 0 1 0 2

V -VDCB NC +VDCB F 0 1 1 3

VI NC -VDCB +VDCB E 0 0 1 1

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Software Design



The s/w implementation for counter-clockwise direction of rotation of the above mentioned commutation table is described below:

const unsigned char BLDC_COMMUTATION_TABLE_CCW[8] = TURN_OFF , /* turn-off */VECTOR_B ,VECTOR_D ,VECTOR_C ,VECTOR_F ,VECTOR_A ,VECTOR_E ,TURN_OFF /* turn-off */;

where:

#define TURN_OFF 0x00#define VECTOR_A 0x06#define VECTOR_B 0x24#define VECTOR_C 0x21#define VECTOR_D 0x09#define VECTOR_E 0x18#define VECTOR_F 0x12

The output vector is then generated on port using command:

Table 6-4. Commutation Table

HS Pattern ResultCommutation Vector

CCWCommutation Vector

CW

0 OFF OFF

1 B E

2 D A

3 C F

4 F C

5 A D

6 E B

7 OFF OFF

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Software DesignSoftware Listing



PTB = BLDC_COMMUTATION_TABLE_CCW[ucSensorVector];

where ucSensorVector is the Hall sensor pattern evaluated from actual state of Hall Sensor.

6.4 Software Listing

The software listing is also available for this Application Note. Special attention was given to the modularity of the code. The code is written in C (Metrowerks® CodeWarrior® for MC68HC08 microcontrollers).

The software consists of the application source code BLDCwithHS_908QY4.c and application header file BLDCwithHS_908QY4.h. The software includes the following software routines:

• main() - It is the entry point following a Reset. It calls the initialization routines and contains the Software Timer.

• MCUInit() - contains initialization of MCU

• ApplicationInit() - contains initialization of application

• VariablesInit() - contains initialization of variables

• StartUpVariablesInit() - contains initialization of variables required for motor start-up

• FaultISR() - contains ISR for DC-Bus over-current hardware fault detection

• OverFlowISR() - contains update of PWM duty cycle and the determination and generation of the commutation vector based on the Hall sensors

• ScanAdc() - scans pot and DC-Bus voltage

• GetReqSpeed() - contains calculation of required speed

• SpeedRamp() - contains speed ramp and DC-Bus over-voltage protection during deceleration

• GetDutyCycle() - contains speed PI controller with calculation of PWM output duty cycle

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Software Design



6.5 Microcontroller Memory and Peripheral Usage

Table 6-5. Memory Usage shows how much memory is needed to run the 3-phase BLDC drive using the MC68HC908QY4 microcontroller. A significant part of the microcontroller memory is still available for other tasks.

The MC68HC908QY4 microcontroller offers many features that simplify the drive design. Table 6-6. MC68HC908QY4 Modules Usage describes the individual available blocks and their use in the introduced system.

Table 6-5. Memory Usage

MemoryAvailable

(MC68HC90QY4)Used

FLASH 4096 Bytes 1650 Bytes

RAM 128 Bytes110 Bytes

(including 80 Bytes Stack)

Table 6-6. MC68HC908QY4 Modules Usage

Module available onMC68HC908QY2/4

Used Purpose

Timer (2-channel) yesPWM generation (TCH0)

Input Capture for measurement of actual motor speed (TCH1)

KeyBoard Interface no

I/O ports yesUser interface, generation of gate

signals

Clock Generation yes on-chip clock generation

COP yes S/W runaway protection

IRQ yes fault protection

LVI yes Low voltage protection

ADC yesSpeed set-up

DC-Bus voltage measurement

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POR yes Reset after Power ON

Table 6-6. MC68HC908QY4 Modules Usage

Module available onMC68HC908QY2/4

Used Purpose

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MOTOROLA References 61


Section 7. References

• MC68HC908QY4 Data SheetsMC68HC908QY4/D, Rev.0.1, Motorola 12/2002

• Application Note “Developer’s Serial Bootloader for M68HC08”, AN2295/D, Motorola 2003

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References


62 References MOTOROLA

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Appendix A — Schematics and Parts ListSchematics


MOTOROLA Appendix A — Schematics and Parts List 63

8.1 Schematics

A set of schematics for the 3-phase BLDC drive appears in Figure 8-1. Microcontroller with Hall Sensor Input and User’s Interface, Figure 8-2. Power Stage and Figure 8-3. Power Supply. Unless otherwise specified, resistors are 1/10 watt, have a ±5% tolerance, and have values shown in ohms. Interrupted lines coded with the same letters are electrically connected.


Section 8. Appendix A — Schematics and Parts List

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Appendix A — Schematics and Parts List


64 Appendix A — Schematics and Parts List MOTOROLA

Figure 8-1. Microcontroller with Hall Sensor Input and User’s Interface

C8

100n

FC

910

0nF

+5V

R50

1k

VC

C

R35

10k

GN

D

+5V

VC

C

R36

10k R

3710

kR38

10k

GN

D

R39

10k

C16

10nF

GN

D

R40

10k

Place close

to U6

Place close

to U5

+5V

J3 HE

AD

ER

3X

2

246

135

+12V

GN

D

GN

D

R1

1k

+5V

R2

1k

+5V

R5

1k

+5V

+

C1

2u2/

20V

PB0 PWM_AT

PB1 PWM_AB

PB2 PWM_BT

PB3 PWM_BB

PB4 PWM_CT

PB5 PWM_CB

C2

100n

F

C4

100n

F+

C3

10uF

/6.3

V

C5

4n7

C6

4n7

C7

4n7

R3

220R

R4

220R

R6

220R

User Interface

Header

GN

D+5

V

R41

0R

+5V

R42

0R

GN

D

Populate with 0ohm

resistor for desired

voltage on HS connector.

NEVER populate both

resistors R41 and R42!

GN

D

J1

CO

N/A

RK

500/

5

1 2 3 4 5

U5C

MC

74H

C03

AD

9 108

U5B

MC

74H

C03

AD

4 56

U5D

MC

74H

C03

AD

12 1311

U5A

MC

74H

C03

AD

1 23

U6B

MC

74H

C03

AD

4 56

U6C

MC

74H

C03

AD

9 108

V_D

CB

US

PW

M_A

T

PW

M_B

T

PW

M_C

B

HS_C

HS_B

HS_A

PW

M_B

B

PW

M_C

T

PTA4 used for

programming using

bootloader

R28

10k

GN

D

Faul

t

GN

D

U6A

MC

74H

C03

AD

1 23

U6D

MC

74H

C03

AD

12 1311

GN

D

GN

D

P1 5k

+5V

GN

D

Hall Sensors

Connector

GN

D+5

VS

W1

RU

N/S

TOP

21 3

U1

MC

68H

C90

8QY

4SO

IC

Vdd

1

PTB

72

PTB

63

PTA

5/O

SC

1/A

D3/

KB

I54

PTA

4/O

SC

2/A

D2/

KB

I45

PTB

56

PTA

3/*R

ST/

KB

I38

PTB

47

PTA

2/IR

Q/K

BI2

9P

TB3

10P

TB2

11P

TA1/

AD

1/TC

H1/

KB

I112

PTA

0/A

D0/

TCH

0/K

BI0

13P

TB1

14P

TB0

15V

ss16

PW

M_A

B

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Appendix A — Schematics and Parts ListSchematics



Figure 8-2. Power Stage

C21

470n

F/25

V

C26

470n

F/25

V Sou

rce_

CT

C25

100n

F

R23

470R

R20

470R

R15

470R

R16

470R

Gat

e_A

T

Gat

e_A

B

Gat

e_C

T

+12V

Faul

t

J2 Pow

er J

ack

+V

1 -V1

2

-V2 3

+12V

+12V

GN

D+12V

L1 CM

V_8

A

R14

0R01

0 - S

BL4

R13

0R01

0 - S

BL4

F1

Fuse

10A

Fas

t

D7

MU

RS

160T

3

D12

MU

RS

160T

3

Gat

e_B

T

VS0

Voltage Range

36Vdc - 56Vdc

Motor

Output

DC Power

Input

+

C24

100u

F/25

V

R11

36k

- 1%

R12

3k -

1%

U2

IR21

32S

HIN

23

LIN

26

HIN

34

LIN

37

HIN

12

LIN

15

FAU

LT8

ITR

IP9

CA

010

CA

-11

VC

C1

VS

S12

VS

126

HO

127

VB

128

LO1

16

LO2

15

LO3

14

HO

223

HO

319

VB

224

VB

320

VS

222

VS

318

VS

013

D6

MB

RS

240L

T3

V_D

CB

US

5V @ (Umax = 65V)

C17

1uF/

250V

DC

+

C18

1000

uF/6

3V

+

C19

1000

uF/6

3V

+C20

1000

uF/6

3V

D8

MB

RS

240L

T3

C35

100n

F

D13

MB

RS

240L

T3

D14

MB

RS

240L

T3

Gat

e_C

B

R17

470R

R19

470R

D11

MB

RS

240L

T3

D9

MB

RS

240L

T3

Gat

e_B

B

D18

MM

SZ5

248B

T1

J4 CO

N/A

RK

750/

2

12J5

CO

N/A

RK

750/

3

1 2 3

Sou

rce_

BT

Sou

rce_

CT

PW

M_A

T

D10

MU

RS

160T

3

PW

M_A

B

PW

M_B

TP

WM

_BB

PW

M_C

TP

WM

_CB

R44

47k

R21

82k

- 1%

D19

MM

SZ5

248B

T1R

4547

kD

20M

MS

Z524

8BT1

R22

8k2

- 1%

R46

47k

Sou

rce_

AT

VS

0

GN

D

Gat

e_A

TG

ate_

BT

Gat

e_C

T

R29

4R7

R30

4R7

D21

MM

SZ5

248B

T1R

4747

k

D5

5KP

60A

R31

4R7

R32

4R7

Q1

IRF3

710

Gat

e_A

B+48V

D23

MM

SZ5

248B

T1R

4847

k

Q2

IRF3

710

Gat

e_C

B

Q3

IRF3

710

D22

MM

SZ5

248B

T1R

4947

k

Gat

e_B

B

Q4

IRF3

710

GN

DQ

5IR

F371

0

R33

4R7

R34

4R7

Q6

IRF3

710

R43

470R

C36

22nF

GN

D

EA

RTH

_GN

D1

Heatsink Grounding

0.5V @ (Imax=10A)

Sou

rce_

AT

Sou

rce_

BT

C23

470n

F/25

V

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Figure 8-3. Power Supply

D16

MB

R16

0

+C

2747

uF/6

3V

+

C32

47uF

/6.3

V

GN

D

GN

DG

ND

U4

MC

78M

05C

DT

IN1

OU

T3

GN

D

2

D15

SM

/1N

4001

J8 GN

D

1G

ND

GN

D

+5V

Range 36V - 56V

1.24V

L233

0uH

12

J7 +5V

1

J6 +12V

1+1

2V+5

V

GN

D

+12V

U3

LT16

76

SH

DN

1

SY

NC

6

Vcc

2

Vsv

3

FB7

Vin5

GND4

Vc

8

C28

100n

F

GN

D GN

D

C33

2200

pF

R27

22

k

R25

91

k -

1%

R26

10

k -

1%

C34

100n

F

GN

D

GN

D

+48V

R24

1k

GN

D

GN

D

D17

GR

EE

N

12V DC

GN

D

C30

100n

FC

3110

0nF

+C

2910

0uF/

25V

GN

D

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Appendix A — Schematics and Parts ListParts Lists



8.2 Parts Lists

The 3-phase BLDC drive’s parts content is described in Table 8-1. Parts List.

Table 8-1. Parts List

Item Designators Qty Description Manufacturer Part Number

1 C1 1 2200nF / 20Vdc tantalum size A Any acceptable

2C2,C4,C8,C9,C25,C28,C30,C31,C34, C35

9 100nF ceramic 0805 Any acceptable

3 C3 1 10µF / 6.3V tantalum size A Any acceptable

4 C5,C6,C7 3 4700pF ceramic 0805 Any acceptable

5 C16 1 10nF ceramic 0805 Any acceptable

6 C17 1metallized polyester capacitor

1.0µF / 250VDCWima MKS 4 0.1/20/250

7 C18,C19,C20 3 1000µF/63V electrolytic capacitor Panasonic ECA1JM102

8 C21,C23,C26 3 470nF/25V ceramic 1206 Any acceptable

9 C24, C29 1 100µF/25V electrolytic ELNA RVK25V101M

10 C27 1 47µF/63V electrolytic Panasonic ECA1JM470

11 C32 1 47µF / 6.3V tantalum size D Any acceptable

12 C33 1 2200pF ceramic 0805 Any acceptable

13 D5 1transient voltage suppressor

60V/5000WFagor, General

Semiconductor5KP60A

14D6,D8,D9,D11,D13,D14

6 2A 40V low Vf Schottky rectifierOn

SemiconductorMBRS240LT3

15 D7,D10,D12 3 1A 600V ultrafast rectifierOn

SemiconductorMURS160T3

16 D15 1 standard recovery diode SMDOn

Semiconductor1N4001

17 D16 1 Schottky diode 1A / 60VOn

SemiconductorMBR160

18 D17 1 green LED SMD Kingbright KP-2012MGC

19D18,D19,D20,D21,D22,D23

6 Zener diode 18V / 0.5WOn

SemiconductorMMSZ5248BT1

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20 F1 1 fuse holder (with fuse 10A fast) MULTICOMP MCHTE15M

21 J1 1 5-pin PCB terminal block Weidmuller LP 5.08/5/90

22 J2 1PCB mounting low voltage DC

power socketSwitchcraft RAPC722

23 J3 1 jumper 2x3 x.1oc Berg Electronics 67997-206H



26 J6, J7, J8 1 test point -

27 L1 1open former common mode

suppression choke 8A/0.74mHRoxburgh CMV80

28 L2 1 330 µH inductance TOKO 822LY-331K

29 P1 1 5kΩ potentiometer 1/2WClarostat Sensors

and Controls, Inc.

392-JB-502

30Q1,Q2,Q3,Q4,Q5,Q6

6HEXFET® Power MOSFET100V / 57A

International Rectifier

IRF3710

31R1,R2,R5,R24,R50

5 1kΩ resistor 1/10W 5% 0805 Any acceptable

32 R3,R4,R6 3 220Ω resistor 1/10W 0805 Any acceptable

33 R11 1 36kΩ resistor 1/10W 1% 0805 Any acceptable


35 R14,R13 2 0.010Ω resistor 4WattMeggitt Polymers

& CompositesSBL4 0R010

36R15,R16,R17,R19,R20,R23

6 24 resistor 1/10W 5% 0805 Any acceptable


38 R22 1 8200Ω resistor 1/10W 1% 0805 Any acceptable




Table 8-1. Parts List (Continued)


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42R28,R35,R36,R37,R38,R39,R40


43R29,R30,R31,R32,R33,R34

6 4.7Ω resistor 1/10W 5% 0805 Any acceptable



44 R41, R42 1

0Ω resistor 0805Note: Populate either R41 or R42

according to the desired voltage on J1 pin 5. Never populate both R41 and R42

Any acceptable

R43 1 0Ω resistor 0805 Any acceptable

45R44,R45,R46,R47,R48,R49


46 SW1 1 PCB mount vertical switchAlcoswitch /

Thomas&BettsTT11DGPC-1FN

47 U1 1 microcontroller MotorolaMC68HC908QY4S

OIC

48 U2 1 3-phase bridge driverInternational

RectifierIR2132S

49 U3 1step-down switching regulator, 7.4-60Vdc input

Linear Technology

LT1676

50 U4 1 linear regulator 5V / 1/2WOn

SemiconductorMC78M05CDT

51 U5, U6 2 quad NAND with open collectorOn

SemiconductorMC74HC03AD

52Install on J3:

pins1-3 and pins2-4

2 shuntSpecialty

Electronics2JM-G

53 no designator 1 heatsink Fisher Elektronik SK 481 85

54 no designator 6 retaining springs for transistors Fisher Elektronik THFU1

55 no designator 6 isolation pads for TO220 Any acceptable

56 no designator 4 screw M3 / 8mm Any acceptable



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57 no designator 1 pot knob Radiatron021-2220type

71-10-1/8-Black

58 no designator 5 Stick-on rubber feet Fastex 5033-01-00-5001



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Appendix B — System Set-upContents


MOTOROLA Appendix B — System Set-up 71

9.1 Contents

9.2 Hardware Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71

9.3 Jumper Settings for Controller Board . . . . . . . . . . . . . . . . . . . .72

9.4 Required Software Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74

9.5 Building and Uploading the Application . . . . . . . . . . . . . . . . . .74

9.6 Executing the Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75

9.2 Hardware Setup

Figure 9-1. Setup of the Application with BLDC Motor illustrates the hardware setup for the application. It incorporates the following modules:

• 3-phase BLDC Drive

• 3-phase BLDC motor with Hall Sensors

• Power supply 48V


Section 9. Appendix B — System Set-up

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Appendix B — System Set-up


72 Appendix B — System Set-up MOTOROLA

Figure 9-1. Setup of the Application with BLDC Motor

9.3 Jumper Settings for Controller Board

The jumper settings for the 3-phase BLDC drive board, shown in Figure 9-2. Jumper Reference of BLDC Drive Board and Table 9-1.BLDC Drive Board Jumper Settings are required to execute the 3-phase BLDC motor control application controlled by the on-board user interface.

Jumper J3 enables selection of an external user interface, as well as microcontroller flash programming using bootloader.

The zero ohms resistors R41 and R42 define the voltage level of power supply for Hall sensors available on pin 5 of Hall sensor connector J1.

• R41 populated with zero ohms resistor for +12Vdc on J5/1

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Appendix B — System Set-upJumper Settings for Controller Board



• R42 populated with zero ohms resistor for +5Vdc on J5/1

WARNING: Please note that only one resistor can be accommodated according to the desired voltage; the other must be disconnected. If both resistors are populated, a short circuit might destroy the board.

Figure 9-2. Jumper Reference of BLDC Drive Board

Pot

PA4

+5V

GN

DPA

5Sw

itch

0R R42 = 0 ohms

R41 not populated J3

Table 9-1. BLDC Drive Board Jumper Settings

Jumper Comment Connections

J3 Run/Stop Switch selected Switch - PA5

J3 Speed Pot selected Pot - PA4

R42 +5Vdc selected for Hall sensor connector J1 pin 5zero ohms

resistor

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9.4 Required Software Tools

The application requires the following software development tools:

• Metrowerks CodeWarrior for Mc68HC08 microcontrollers version 2.1 or later.

• Bootloader for 908QY4

9.5 Building and Uploading the Application

The application software is delivered as BLDCwithHS_908QY4.mcp project file with C-source and header files BLDCwithHS_908QY4.c and BLDCwithHS_908QY4.h. Using Metrowerks CodeWarrior the executable S19 file can be created. The executable file is then downloaded into MCU through the serial bootloader, or using other Motorola programming tools.

The Developer’s Serial Bootloader for M68HC08 is a low-cost, in-circuit programming solution. It allows in-circuit reprogramming of Motorola’s M68HC08 FLASH devices using standard communication media (e.g., a serial asynchronous port). Once the MCU is pre-programmed with the bootloader, the MCU memory can be modified in-circuit. Because of its ability to modify MCU memory in-circuit, the serial bootloader is an M68HC08 MCU utility that may be useful in developing applications. Please note that the bootloader can be used only for reprogramming, not for in-circuit debugging. The bootloader is described in detail in AN2295/D “Developer’s Serial Bootloader for M68HC08“.

For MCU Flash memory programming, pin PTA4 on the BLDC board should be used. The bootloader programmer is then connected to this pin - with of course, the jumper removed, disconnecting the Run/Stop switch.

R41+12Vdc not used for Hall sensor connector J1 pin 5

due to selection of +5Vdc on this pinNo connection

Table 9-1. BLDC Drive Board Jumper Settings

Jumper Comment Connections

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Appendix B — System Set-upExecuting the Application



9.6 Executing the Application

The application is prepared for operation when connected to a power supply.

The drive is controlled by the RUN/STOP switch (SW1). The motor speed is set by the SPEED potentiometer (P1). If successful, the 3-phase BLDC motor will be spinning.

NOTE: If the RUN/STOP switch is set to the RUN position when the application is powered on, toggle the switch between the RUN and STOP positions to enable motor spinning. This is a protection feature preventing the motor from starting after power on.

In the case of a DC Bus over-current, DC Bus over-voltage or DC Bus under-voltage, the fault protection disables the drive. The DC Bus over-current fault state can be left by turning the RUN/STOP switch to the stop position. DC Bus over-voltage or DC Bus under-voltage fault state can be left by MCU reset.

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HOW TO REACH US:

USA/EUROPE/LOCATIONS NOT LISTED:

Motorola Literature Distribution; P.O. Box 5405, Denver, Colorado 80217 1-303-675-2140 or 1-800-441-2447

JAPAN:

Motorola Japan Ltd.; SPS, Technical Information Center, 3-20-1, Minami-Azabu Minato-ku, Tokyo 106-8573 Japan81-3-3440-3569

ASIA/PACIFIC:

Motorola Semiconductors H.K. Ltd.; Silicon Harbour Centre, 2 Dai King Street, Tai Po Industrial Estate, Tai Po, N.T., Hong Kong852-26668334

TECHNICAL INFORMATION CENTER:

1-800-521-6274

HOME PAGE:

http://motorola.com/semiconductors

Information in this document is provided solely to enable system and software

implementers to use Motorola products. There are no express or implied copyright

licenses granted hereunder to design or fabricate any integrated circuits or

integrated circuits based on the information in this document.

Motorola reserves the right to make changes without further notice to any products

herein. Motorola makes no warranty, representation or guarantee regarding the

suitability of its products for any particular purpose, nor does Motorola assume any

liability arising out of the application or use of any product or circuit, and specifically

disclaims any and all liability, including without limitation consequential or incidental

damages. “Typical” parameters which may be provided in Motorola data sheets

and/or specifications can and do vary in different applications and actual

performance may vary over time. All operating parameters, including “Typicals”

must be validated for each customer application by customer’s technical experts.

Motorola does not convey any license under its patent rights nor the rights of

others. Motorola products are not designed, intended, or authorized for use as

components in systems intended for surgical implant into the body, or other

applications intended to support or sustain life, or for any other application in which

the failure of the Motorola product could create a situation where personal injury or

death may occur. Should Buyer purchase or use Motorola products for any such

unintended or unauthorized application, Buyer shall indemnify and hold Motorola

and its officers, employees, subsidiaries, affiliates, and distributors harmless

against all claims, costs, damages, and expenses, and reasonable attorney fees

arising out of, directly or indirectly, any claim of personal injury or death associated

with such unintended or unauthorized use, even if such claim alleges that Motorola

was negligent regarding the design or manufacture of the part.

Motorola and the Stylized M Logo are registered in the U.S. Patent and Trademark Office. digital dna is a trademark of Motorola, Inc. All other product or service names are the property of their respective owners. Motorola, Inc. is an Equal Opportunity/Affirmative Action Employer.

© Motorola, Inc. 2003

DRM046

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