SG6840 Ver la hoja de datos (PDF) - Unspecified

Número de pieza

componentes Descripción

Fabricante

SG6840

High-integrated Green Mode PWM Controller

Unspecified 

SG6840

Product Specification

PIN DESCRIPTIONS

Name Pin No.

VDD

7

VIN

3

FB

2

Sense

6

RT

5

Gate

8

Ri

4

GND

1

Type Function

Supply Power supply.

Analog in-

put

The start-up current input. A start-up resistor is connected from the

line-input to this pin, such as 1.5MΩ for off-line converter. Adjust the

start-up resistor to vary the line voltage compensation for constant

Analog in- Feedback. The FB pin provides the information of the regulation, it

put

effects to the internal PWM comparator to control the duty cycle.

Current sense. It senses the voltage developed on a sensed resistor.

Analog in- When it reaches the internal threshold, the PWM output is disabled.

put

Therefore, the over-current protection is realized. Besides, the current

information is providing for the current mode control.

For over-temperature protection. A constant current is output.

Analog in- An NTC thermistor is connected from this pin to ground to sense the

put/output temperature. When the voltage in this pin is lower than the limit,

which will enable the over-temperature protection.

Driver out- The totem-pole output driver to drive the power MOSFET.

Program- Reference setting. Connect a resistor to ground to generate a con-

Supply Ground.

BLOCK DIAGRAM

Ri

4

VDD

VIN 3

VDD 7

RT 5

0.8V

+

_AI

+ UVLO

_

16V/10V

Internal

BIAS

I RT

+

_

0.7V

Soft

ON/OFF

Driver

8 Gate

QS

R

OSC

Green Mode

Controller

Comp

Comp

6 Sense

Slope

Compensation

5V

2 FB

1

GND

2002 System General Corporation

-2-

Ver1.0

http://www.sg.com.tw

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