gr8841 datasheet v1.01-20100419 - grenergy-ic.com mode... · lcd tv/monitor power supply ......

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


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


GR8841

Block Diagram


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


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


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)


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)


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.


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.


GR8841

Typical Application Circuit


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


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


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.


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.


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.

gr8841 datasheet v1.01-20100419 - grenergy-ic.com mode... · lcd tv/monitor power supply ......

Documents