gr8841 datasheet v1.01-20100419 - grenergy-ic.com mode... · lcd tv/monitor power supply ......
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2010.04 Ver.1.01 Copyright Grenergy OPTO, Inc. www.grenergy-ic.com 1
GR8841
Features � Current mode PWM controller
� Very low startup current
� Under-voltage lockout (UVLO)
� Soft start function
� Non-audible-noise green-mode control
� Programmable switching frequency
� Internal leading-edge blanking
� Internal slope compensation
� Gate output at typical 18V voltage clamp
� Over-voltage protection (OVP) on VCC pin
� Over-load protection (OLP)
� Over-current protection (OCP) with high and
low line compensation
� Over-temperature protection (OTP)
programmable
Applications ● LCD TV/Monitor power supply ● Networking power supply ● Notebook computer adapter
Description The highly integrated PWM controller GR8841
provides several features to enhance the
performance of flyback converters. The CMOS
process allows low start-up current and operating
current. A proprietary green-mode function provides
off-time modulation to continuously decrease the
switching frequency at light-load conditions. This
function enables the power supply to easily meet
international power conservation requirements.
For limiting the Vds at power on, the soft start
function is integrated in GR8841.
GR8841 provides many protection functions
including OLP, OVP, OCP, OTP protection. A
brownout comparator is implemented to detect the
abnormal line condition then shutdown the controller
to prevent the damage. The gate voltage is clamped
about 18V to protect the external power MOSFET
from being damaged by supply over voltage. An
external NTC thermistor can be applied for
over-temperature protection. GR8841 is available in
a SOP-8 or DIP-8 package.
Ordering and Marking Information
DIP-8/SOP-8
Code 1 8 9 A B G H I J Year 2008 2009 2010 2011 2016 2017 2018 2019 Code 2 1 2 3 4 9 A B C Month Jan. Feb. Mar. Apr. ● ● ● Sep. Oct. Nov. Dec. Grenergy OPTO Inc. reserves the right to make changes to improve reliability or manufacture ability without notice, and
advise customers to obtain the latest version of relevant information to verify before placing orders.
Green-Mode Controller for Switching Mode Power Supply
2010.04 Ver.1.01 Copyright Grenergy OPTO, Inc. www.grenergy-ic.com 2
GR8841
Pin Configuration
Top View
Pin Description
Pin No. Symbol Description
1 GND Ground
2 FB Voltage feedback pin, by connecting a photo-coupler to control the duty cycle
3 VIN VIN pin is pulled high to the rectified line input through a resistor for start-up
4 RI
A resistor from RI pin to ground will generate a constant current source. This
current is used to charge an internal capacitor and the external RI resistor to
determine the switching frequency.
5 RT For over-temperature protection, it is programmable
6 SENSE Current sense pin, connect to sense the MOSFET current
7 VCC Power supply pin
8 GATE The gate for driving the external MOSFET
Absolute Maximum Ratings
Supply voltage VCC ---------------------------------------------------------------------------------------------------------- 35V
COMP, RT, CS ---------------------------------------------------------------------------------------------------------- -0.3 ~ 7V
OUT ------------------------------------------------------------------------------------------------------------ -0.3 ~ VCC + 0.3V
Junction temperature ------------------------------------------------------------------------------------------------------ 150℃
Operating ambient temperature -------------------------------------------------------------------------------- -40℃ ~ 85℃
Storage temperature range ------------------------------------------------------------------------------------ -65℃ ~ 150℃
SOP-8 package thermal resistance -------------------------------------------------------------------------------- 160℃/W
DIP-8 package thermal resistance ---------------------------------------------------------------------------------- 100℃/W
Power dissipation (SOP-8, at ambient temperature = 85℃) --------------------------------------------------- 400mW
Power dissipation (DIP-8, at ambient temperature = 85℃) -------------------------------------------------- 650mW
Lead temperature (All Pb free packages, soldering, 10 sec) ---------------------------------------------------- 260℃
ESD voltage protection, human body model --------------------------------------------------------------------------- 3KV
ESD voltage protection, machine model ------------------------------------------------------------------------------- 250V
2010.04 Ver.1.01 Copyright Grenergy OPTO, Inc. www.grenergy-ic.com 3
GR8841
Block Diagram
2010.04 Ver.1.01 Copyright Grenergy OPTO, Inc. www.grenergy-ic.com 4
GR8841
Electrical Characteristics (TA = +25℃ unless otherwise stated, VCC = 15.0V)
Parameter Pin Min. Typ. Max. Unit
SUPPLY VOLTAGE
Startup current 7 8 20 uA
Operating current (with 1nF load on OUT pin), Vcomp = 0V 7 2.0 3.0 mA
Operating current (with 1nF load on OUT pin), Vcomp = 2.5V 7 2.5 mA
Operating current (with 1nF load on OUT pin), protection tripped
(OLP, OVP) 7 0.8 mA
UVLO (off) 7 9.0 10.0 11.0 V
UVLO (on) 7 15.0 16.0 17.5 V
OVP level on VCC pin 7 27 28.5 30 V
VOLTAGE FEEDBACK
Short circuit current, Vcomp = 0V 2 1.0 1.5 mA
Open loop voltage, COMP pin open 2 5.2 V
Green-mode threshold voltage 2 1.8 V
CURRENT SENSING
Maximum input voltage, Vcs (off) 6 0. 85 0.90 0.95 V
Leading-edge blanking time 6 350 nS
Input impedance 6 1 MΩ
Delay to output 6 100 nS
OSCILLATOR (RI SECTION )
Frequency (RI = 26KΩ) 4 60 65 70 KHz
Green mode frequency (RI = 26KΩ) 4 22 KHz
Temp. stability (-40°C ~ 85°C) 4 3 %
Voltage stability (VCC = 11V ~ 25V) 4 3 %
GATE DRIVER OUTPUT
Output low level, VCC = 15V, Io = 20mA 8 1.5 V
Output high level, VCC = 15V, Io = 20mA 8 8 V
Rising time, load capacitance = 1000P 8 150 250 350 nS
Falling time, load capacitance = 1000P 8 30 50 90 nS
VGATE-clamp (VCC = 25V ) 8 18 V
Maximum duty cycle 8 75 %
Soft start - 4 mS
OLP
OLP trip level, VFB (OLP) - 4.2 V
OLP delay time (note), Fs = 65KHz - 60 mS
2010.04 Ver.1.01 Copyright Grenergy OPTO, Inc. www.grenergy-ic.com 5
GR8841
Electrical Characteristics (Cont.)
Parameter Pin Min. Typ. Max. Unit
RT SECTION
Output current of RT pin 5 100 uA
Trigger voltage for over temp. protection 5 0.62 V
OTP release voltage 5 0.65 V
Over temp. de-bounce @ 65KHz 5 60 100 140 us
2010.04 Ver.1.01 Copyright Grenergy OPTO, Inc. www.grenergy-ic.com 6
GR8841
6789101112-40 0 40 80 120Temperature(℃)Start-up Curre
nt (uA)
Typical Performance Characteristics
15.515.715.916.116.316.5-40 0 40 80 120Temperature(℃)UVLO Rising (o
n) Voltage(V)
9.69.81010.210.4
-40 0 40 80 120Temperature(℃)UVLO Falling (off) Voltage(V)
Fig.1
586062646668-40 0 40 80 120Temperature(℃)
Frequency(kHz)
Fig.3
Fig.5
Fig.2
Fig.4
1.822.22.42.62.8-40 0 40 80 120Temperature(℃)Operating Curr
ent (mA)
Fig.6
21.121.321.521.721.922.1-40 0 40 80 120Temperature(℃)Green Mode Fre
quency(Khz)
2010.04 Ver.1.01 Copyright Grenergy OPTO, Inc. www.grenergy-ic.com 7
GR8841
Typical Performance Characteristics
(Cont.)
0.580.60.620.640.660.68-40 0 40 80 120Temperature(℃)OTP Trim Level
(V)
Fig.7
0.880.90.920.940.960.98-40 0 40 80 120Temperature(℃)OCP Trim Level
(V)
Fig.9
Fig.11
Fig.8
11.051.11.151.21.25-40 0 40 80 120Temperature(℃)brown-out Tri
m Level (V)
Fig.10
Fig.12
717273747576
-40 0 40 80 120Temperature(℃)Maximum Duty of PWM (%)
3.944.14.24.34.4-40 0 40 80 120Temperature(℃)OLP Trim Level
(V)27.82828.228.428.628.8
-40 0 40 80 120Temperature(℃)OVP Trim Level(V)
2010.04 Ver.1.01 Copyright Grenergy OPTO, Inc. www.grenergy-ic.com 8
GR8841
Application Information
Start-up Current
The typical start-up current is 8uA. Very low start-up
current allows the PWM controller to increase the
value of start-up resistor and then reduce the power
dissipation on it.
Under-voltage Lockout (UVLO)
A hysteresis UVLO comparator is implemented in
GR8841, then the turn-on and turn-off thresholds
level are fixed at 16V and 10V respectively. This
hysteresis shown in Fig.13 ensures that the start-up
capacitor will be adequate to supply the chip during
start-up.
Fig.13
Soft Start
During initial power on, the GR8841 provides soft
start function. It effectively suppresses the start up
peak current to reduce the power MOSFET drain
voltage especially at high line.
Oscillator
The maximum duty-cycle of internal oscillator is
limited about 75% to avoid the transformer
saturation. The frequency of the oscillator is decided
by an external resistor connected from RT pin to
ground.
Fosc (KHz) = 1690 / RI(Kohm)
Where RI is the resistor connected at RI pin. A 26K
Ohm resistor results in 65KHz switching frequency.
The recommended range of oscillation frequency is
50 KHz~110 KHz.
Green-mode Operation
When the load decreases to an extent, the
frequency of the controller will decrease so as to
reduce the system power consumption. The
minimum frequency is typical 22 KHz, which is
outside the audio range.
Leading-edge Blanking (LEB)
Each time the power MOSFET is switched on, a
turn-on spike will inevitably occur at the sense
resistor. To avoid fault trigger, a 350ns leading-edge
blanking time is built in. Conventional RC filtering
can therefore be omitted. During this blanking
period, the current-limit comparator is disabled and
can not switch off the gate driver.
Internal Slope Compensation
A built-in slope compensation circuit is constructed
in GR8841. When the switch is on, a ramp voltage
is added to the sensed voltage across the CS pin,
which helps to stabilize the system and prevent
sub-harmonic oscillations.
Over-load Protection (OLP)
The controller has over-load protection function.
An internal circuit detects the load level, when the
load is larger than a threshold and the condition
lasts more than 60ms, the gate output will keep low
level. Then VCC decreases below UVLO off level,
the controller resets again. Fig.14 shows the
waveform of the OLP operation.
2010.04 Ver.1.01 Copyright Grenergy OPTO, Inc. www.grenergy-ic.com 9
GR8841
Over-voltage Protection (OVP) on VCC
To prevent power MOSFET from being damaged,
the GR8841 is implemented an OVP function on
VCC. When the VCC voltage is higher than the OVP
threshold voltage, the output gate driver circuit will
be shut down immediately to stop the switching of
power MOSFET.
The OVP function is an auto-recovery type. Topped
and recover at the next UVLO on. The GR8841 is
working in a hiccup mode.
Gate Clamp/Soft Driving
Driver is clamped at 18V with a totem pole output.
Those damages usually come from undesired
over-voltage gate signals. Under the conditions
listed below, the gate output will turn off immediately
to protect the power circuit. The GR8841 also has
soft driving function to minimize EMI.
Over-temperature Protection (OTP)
A NTC resistor is connected from Pin RT to ground.
A constant current flows from RT pin. When ambient
temperature gets higher, the NTC resistor will be
smaller such that VRT is less than 0.62V. The PWM
will be completely turned off.
2010.04 Ver.1.01 Copyright Grenergy OPTO, Inc. www.grenergy-ic.com 10
GR8841
Typical Application Circuit
2010.04 Ver.1.01 Copyright Grenergy OPTO, Inc. www.grenergy-ic.com 11
GR8841
Bom List
Ref. Des Description Vendor QTY
BD1 Bridge, KBL406, DIP - 1
CX X-cap, 0.47uF, 275V, DIP WB 1
C1 E-Cap, 120uF, 400V, 105℃, DIP SAMXON 1
C2 E-Cap, 10uF, 50V, 105℃, DIP Canicon 1
C3,C4 E-Cap, 470uF, 25V, 105℃, DIP, Low ESR CapXON 2
C5 E-Cap, 330uF, 25V, 105℃, DIP, Low ESR Lelon 1
C7, C15 Cap,102, 50V, SMD 0805 2
C9, C12, C14 N.A. - -
C8 Cap, 472, 1KV, DIP WB 1
C10 Cap, 222, 50V, SMD 0805 - 1
C11 Cap, 222, 1KV, DIP WB 1
C16 (parallel with R19) Cap,103, 50V, SMD 0805 - 1
C17 (parallel between
Q2 Pin 1& Pin3) Cap,103, 50V, SMD 0805 - 1
CN1 AC Input (3 Pin) - 1
CR1 FR104, DIP Diodes 1
CR2 FR107, DIP Diodes 1
CR3 1N4148, SMD - 1
CR4, CR6 MBRF10100 Diodes 2
CR5 N.A. - -
CY1 Y1-CAP, AH332M, 250V TDK 1
F1 3.15A, 250V, DIP - 1
G2 GND2 - 1
HS1 Heat sink of Rectifier - 1
HS2 Heat sink of MOSFET - 1
LF1 Common Chock, 700uH,DIP Generic 1
LF2 Common Chock, 20mH, DIP Generic 1
L3 1.6uH, DIP Generic 1
NTC1 NTC 5D-9 - 1
NTC2 N.A. - -
PCB FR4,107mm * 85.3mm * 1.6mm - 1
2010.04 Ver.1.01 Copyright Grenergy OPTO, Inc. www.grenergy-ic.com 12
GR8841
Bom List (Cont.)
Ref. Des Description Vendor QTY
Q1 K2843, T0220 Toshiba 1
Q2 GL431 Grenergy 1
R1, R2, R3, R4 1M, 5%, SMD 1206 - 4
R6 27K,1%, SMD 0805 - 1
R9, R10, R11, R12 100K, 5%, SMD 1206 - 4
R13, R18, R25 N.A - -
R14 47R, 5%, SMD 1206 - 1
R15 33 Ohms, DIP - 1
R16 3.3R, 5%, SMD 1206 - 1
R17 39K, SMD0805 - 1
R19 33K, 1%, SMD 0805 - 1
R20A, R20B 10K, 1%, SMD 0805 - 2
R21 0R, SMD 0805 - 1
R22, R23 33R, 5%, SMD 1206 - 2
R24 1K, 5%, SMD 0805 - 1
RCS 0.36R, 1W, DIP - 1
W1 Jumper - 1
T3 P0T-3019, 550uH Newline universal 1
U1 GR8841, SOP-8 Grenergy 1
U2 PC817, DIP Sharp 1
2010.04 Ver.1.01 Copyright Grenergy OPTO, Inc. www.grenergy-ic.com 13
GR8841
Package Information
DIP-8
MILLIMETERS INCHES SYMBOL
MIN. MAX. MIN. MAX.
A 5.33 0.210
A1 0.38 0.015
A2 2.92 4.95 0.115 0.195
b 0.36 0.56 0.014 0.022
b2 1.14 1.78 0.045 0.070
c 0.20 0.35 0.008 0.014
D 9.01 10.16 0.355 0.400
D1 0.13 0.005
E 7.62 8.26 0.300 0.325
E1 6.10 7.11 0.240 0.280
e 2.54 BSC 0.100 BSC
eA 7.62 BSC 0.300 BSC
eB 10.92 0.430
L 2.92 3.81 0.115 0.150
Note: 1. Followed from JEDEC MS-001 BA.
2. Dimension D, D1 and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not
exceed 10 mil.
2010.04 Ver.1.01 Copyright Grenergy OPTO, Inc. www.grenergy-ic.com 14
GR8841
Package Information
SOP-8
MILLIMETERS INCHES SYMBOL
MIN. MAX. MIN. MAX.
A 1.75 0.069
A1 0.10 0.25 0.004 0.010
A2 1.25 0.049
b 0.31 0.51 0.012 0.020
c 0.17 0.25 0.007 0.010
D 4.80 5.00 0.189 0.197
E 5.80 6.20 0.228 0.244
E1 3.80 4.00 0.150 0.157
e 1.27 BSC 0.050 BSC
h 0.25 0.50 0.010 0.020
L 0.40 1.27 0.016 0.050 θ 0o 8
o 0
o 8
o
Note: 1. Followed from JEDEC MS-012 AA.
2. Dimension “D” does not include mold flash, protrusions or gate burrs. Mold flash, protrusion or gate
burrs shall not exceed 6 mil per side.
3. Dimension “E1” does not include inter-lead flash or protrusions. Inter-lead flash and protrusions shall
not exceed 10 mil per side.
2010.04 Ver.1.01 Copyright Grenergy OPTO, Inc. www.grenergy-ic.com 15
GR8841
Carrier Tape & Reel Dimensions
SOP- 8
Application A H T1 C d D W E1 F
330.0±2.0 50 MIN. 12.4+2.00
-0.00
13.0+0.50
-0.20 1.5 MIN. 20.2 MIN. 12.0±0.30 1.75±0.10 5.5±0.05
P0 P1 P2 D0 D1 T A0 B0 K0 SOP-8
4.0±0.10 8.0±0.10 2.0±0.05 1.5+0.10
-0.00 1.5 MIN.
0.6+0.00
-0.40 6.40±0.20 5.20±0.20 2.10±0.20
(mm)
Devices Per Unit
Application Carrier Width Cover Tape Width Devices Per Reel
SOP- 8 12 - 2500
________________________________________________________________________ Grenergy OPTO, Inc. reserves the right to make corrections, modifications, enhancements, improvements, and other changes
to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the
latest relevant information before placing orders and should verify that such information is current and complete.