simple layout class 1

Network and Systems Laboratorynslab.ee.ntu.edu.tw

2010/12/10Wireless Sensor Network And Labs fall 2010 1


Making A Hardware BoardDefine system requirements

Finding components and

design circuit

Capture Schematic

Printed Circuit Board (PCB)

layout

Professional PCB

manufacturers

Home made PCB prototype

PCB board

Soldering Components

Testing



Typical Process1. Define requirements2. Get the circuits

Design from scratch Google Ask some one who know

2. Find components Which IC you want to use

3. Create component libraries in the PCB software4. Capture schematic

Draw the circuit on the PCB software5. Layout

1. Decide the shape of the board2. Placing components3. Make connections

6. Make the hardware board Export layout to manufacturer output, send to PCB

manufacturer Home made PCB 2010/12/10

Wireless Sensor Network And Labs fall 2010 3


Today’s ClassIntroductionCreate schematic libraryCapture schematicNext week

Create PCB library (footprint)Layout



First Of All -- SchematicRectangle with pin names are usually components

Rectangle with numbers are usually connector

Usually on the schematic or their description, they will tell you what component it is (part number). You can find the datasheet of the component from Internet



Taroko Schematic

Light sensors

LEDs

Switches



Real Device And SchematicThere will be a designator for each component on schematic. And it is 1-to-1 map to the PCB board



Map to Real Device



Resources Available On InternetBooks GoogleApplication notes

A document which gives more specific details on using a component in a specific application

Provided by IC manufacturers Example: TI MSP430 application notes

Reference designEspecially RF ICExample: CC2420 reference design



Search For DatasheetM25P80

Datasheet 8 Mbit, low voltage, serial Flash memory with 75 M

Hz SPI bus interfaceIt is a flash memory

SHT11Datasheet

SHT1x / SHT7xTemperature and Humidity Sensor



What To Look In DatasheetFunctionality

What does this IC doElectrical Characteristic

Supply voltageCurrent consumptionEtc

Application InformationHow to make it work

PackagesWhat is the IC looks likeShape, size, pins design, pitch, etc.



M25P80 Datasheet

SPI interface



M25P80 Signal Description

SPI interface



Connect M25P80 and MSP430

SPI interface on MSP430

Pin 2, 5, 6 is SPI interface on M25P80, connected to SPI interface of MSP430

Chip select and Hold pin connected to GPIO pins on MSP430

Write Protect is connected to Vcc, that means we are not using write protect function

GPIO on MSP430

The SPI interface is shared with radio chip



M25P80 DatasheetUsually at the end of the datasheet, there will

be some section call “Packaging information”, “Package”, ……

This section contain the information about how the chip looks like

Lets take a look at the common packages



M25P80 PackagesA chip may

have more than one packageM25P80 has

three Package

information gives you the footprint of the chip



SO8W We use M25P80 SO8W package on Taroko

A dot here defines pin #1

E E1

eb



Through-hole vs SMDThrough-hole

A mounting scheme Pins inserted into holes drilled in PCB and

soldered to pads on the opposite side Expansion connector on Taroko Light sensor on Taroko

SMD: surface mounted deviceComponents are mounted directly onto the

surface of PCB Many devices on Taroko are SMD Resistor, capacitor, MSP430, and more.



Through-hole PackagesSIP: single in-line packages

DIP: dual in-line packages

Through-hole package are old, their number decreased in modern design



SMD PackagesChip resistors, capacitors, inductors

0402, 0603, 0805, … Represent size of the chip 0805 means 0.08” x 0.05” rectangle



SMD Packages SO: Small outline

Usually refer to IC with two rows of leads

QFP: Quad flat package



SMD Packages QFN: Quad flat package, no-leads

The packages we introduced just now are most commonly usedDevice datasheet should include the package

informationYou will need it for PCB layout



SMD Packages BGA: Ball Grid Array

PGA: Pin Grid Array

These two are widely used in high end processor. They allow more pin-out from a single package. We seldom use ICs in these package, it is too difficult to solder by hand



Power

MSP430 USBCC2420 Radio

Sensors, memory, LEDs, switches,

expension

Power

what about Power???

USB is 5V, MSP430 operating range is 1.8V ~ 3.6V. How to get supply power from USB?

USB is 5V, MSP430 operating range is 1.8V ~ 3.6V. How to get supply power from USB?



RegulatorA semiconductor device that converts an input

DC voltage (usually a range of input voltages) to a fixed-output DC voltage

Many types of regulators, most commonly usedLinear regulatorsSwitching regulators

You might accept power supply from various sources with different voltage, but you need a stable voltage for your systemUse a regulator

Regulator

input output(5V ~ 40V) 3.3V (fixed)



Linear RegulatorOutput voltage < input voltage

All linear regulators require an input voltage at least some minimum amount higher than the desired output voltage This minimum amount is called drop-out voltage

You can only step down the voltageInefficient, power dissipated as heat

Linear regulator

input output(3.3V) 5V

Regulator

input output(5V ~ 40V) 3.3V (fixed)

Taro

ko

Taroko current consumption=60mA

Power provided at the output = 3.3V * 60mA = 198mW

Power provided at the output = 5V * 60mA = 300mW

Power dissipated on regulator = 300mW – 198mW = 102mW

Switching Regulator can step up the voltage



Key Parameters of RegulatorsInput voltage range

A range of possible input voltageOutput voltage

Fixed to some valueAdjustable

Can be adjust by some external resistors

Maximum output currentMaximum current allowed

Drop-out voltage



Linear Regulator ICsMCP1700T-3302TT (on Taroko)

U25 on Taroko



Typical Application CircuitUsually the datasheet has the typical

application circuit



Why To BuyYou have a schematic, and already found out

what is the components on itBut, where to buy?

Various sourcesOnline retailers

www.digikey.com www.mouser.com

Local distributors

These are probably two of the world largest online electronic

components retailers. If the component you need cannot buy

from these two sources, you might want to consider the other

component!



Putting Things TogetherHardware prototyping

BreadboardPrinted Circuit Board



Breadboard

Fast and easy Signal unstable and

inaccurate Ugly! Un-professional



Printed Circuit Board

Take some time Professional Signal is more stable

Home made PCB

Industry fabrication PCB



GoalDesign a term project control board

Replace the BreadboardPlace on you robot carHas Connectors to connect two Taroko’s

Location node Control node: receive infrared, control motor, receive

locationProvide power supply for TarokoHas connectors to connect two infrared sensorsHas connectors to connect two motor (PWM

output)



Block Diagram

TarokoLocation node

TarokoControl node

Battery4 AA

6V output

Regulator

LM317L

Connector

3-PinInfrared

Connector

3-PinInfrared

Connector

3-PinMotor

Connector

3-PinMotor

3.3V

3.3V

6V

6V



ComponentsBattery connector: 2-pin, Regulator: LM317L, 8-pin SOIC

Resistor, capacitorTaroko connector

Location node: 2x5 pin, 2x3 pin Control node: 2x5 pin, 2x3 pin

Infrared connector: 3 pin Motor connector: 3 pin



PCB LayoutSoftware

We are using “Altium Design 6”There are many other software available

Process1.Initial setup2.Create schematic library3.Capture schematic4.Create PCB library5.PCB layout6.Output



ToolsAltium Designer

http://www.altium.com/products/altium-designer/en/altium-designer_home.cfm

Trial versionhttps://trial1.altium.com/?lang=us#:1sy923989



Altium Designer 6 Electronic product development solution

Schematic capturePCB Board designSimulationFPGA designetc.

We will use it to do the PCB layout



PCB Layout ProcessProcess

1. Initial setup1. Create design workspace 2. Create PCB project3. Add new “Schematic”, “PCB”, “Schematic library”

and “PCB library”

2. Create schematic library3. Capture schematic4. Create PCB library5. PCB layout6. Output



Schematic LibraryComponent list (what components you need)

LM317LMiscellaneous components

Resistor capacitor connectors

Schematic library contain the components you will useAltium Designer has a collection of libraries

Search the libraries If the components you want is not in the libraries provide, you

have to create one (both AD7798, ADXL330 was not found) Create library components for AD7766 and ADXL330

Copy Miscellaneous components



Capture SchematicSchematic library are readyCapture Schematic

0102

Vcc

Vcc

Vcc

Vcc

2468REFIN(-),

AIN1(-), AIN2(-), AIN3(-) connect GND

GND

XoutYout

Zout

Give every power supply line a 0.1 μF capacitor



The Schematic



Create your own schematic


simple layout class 1

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