SG6841D Ver la hoja de datos (PDF) - Unspecified

Número de pieza

componentes Descripción

Fabricante

SG6841D

High-integrated Green-mode PWM Controller

Unspecified 

High-integrated Green-mode PWM Controller

MARKING DIAGRAMS

SG6841TP

XXXXXXXYYWWV

T: D = DIP, S = SOP

P: Z = Lead Free

Null=regular package

XXXXXXX: Wafer Lot

YY: Year; WW: Week

V: Assembly Location

Product Specification

SG6841

PIN CONFIGURATION

GND

FB

VIN

RI

GATE

VDD

SENSE

RT

ORDERING INFORMATION

Part Number

Package

SG6841S

8-Pin SOP

SG6841D

8-Pin DIP

SG6841SZ

8-Pin SOP(Lead Free)

SG6841DZ

8-Pin DIP(Lead Free)

PIN DESCRIPTIONS

Pin No. Symbol Function

Description

1

GND

Ground

Ground.

The signal from external compensation circuit is feed into this pin. The PWM duty cycle is

2

FB

Feedback

determined by this FB pin and current sense signal from Pin 6.

This pin is pulled high to the rectified line input through a resistor for start-up. Since the

start-up current requirement for SG6841 is very small, a large start-up resistance can be

3

VIN

Start-Up Input

used to minimize power loss. Under normal operation, this pin is also used to detect line

voltage to compensate for constant output power limit for universal AC input.

A resistor from RI pin to ground will generate a constant current source forSG6841. This

current is used to charge an internal capacitor and hence the switching frequency are

4

Ri

Reference Setting determined. Increasing the resistance will decrease the current source and reduce the

switching frequency. A 26kΩ resistor Ri creates a 50uA constant current Ii and generates

65kHz switching frequency.

For over-temperature protection. An external NTC thermistor is connected from this pin

Temperature

5

RT

to ground. The impedance of the NTC will decrease under high temperature. Once the

Protection

voltage on RT pin drops below a fixed limit, the PWM output will be disabled.

Current sense. The sensed voltage is used for current mode control and pulse-by-pulse

6

SENSE Current Sense

current limiting.

7

VDD

Power supply

Power Supply.

The totem-pole output driver for the power MOSFET. A soft driving waveform is

8

GATE

Driver Output

implemented to improve EMI.

©System General Corp.

-2-

Version 2.1 (IRO33.0001.B5)

www.sg.com.tw

Jun.15,2006

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