Copyright  ANPEC Electronics Corp.

Rev. A.7 - Jan., 2003

APW38HC42A/3A/4A/5A

www.anpec.com.tw

2

Duty Cycle

Startup 8.4V

Minimum Operating 7.6V

Startup 14.5V

Minimum Operating 9V

0~96%

APW38HC43A

APW38HC42A

0~50%

APW38HC45A

APW38HC44A

Block Diagram

Functional Pin Description

Pin Name

Pin Number

Function Description

1

COMP

Compensation: Connect external compensation network to

modify the error amplifier output.

2

FB

Feedback (Input): Error amplifier input. Feedback is 2.5V at

desired output voltage.

3ISNS

Current Sense (Input): Current sense comparator input.

Connect to current sensing resistor or current transformer.

4

RT/CT

Timing Resistor/Timing Capacitor: Connect external RC

network to select switching frequency.

5

GND

Ground: Combined analog and power ground.

6

OUT

Power Output: Totem-pole output.

7VDD

Analog Supply (Input): Controller circuitry supply input. Return

to analog ground (AGND).

8

VREF

5V Reference (Output): Connect external RC network.

UVLO

T

Q

Oscillator

5V

Reference

S

Q

R

+

-

+

-

OUT

ISNS

GND

COMP

2.5V

FB

RT/CT

VREF

VDD

R

2R

E. A.

Selection Guide