CP494

SWITCHMODE Pulse Width Modulation Control Circuit

* All specs and applications shown above subject to change without prior notice.

1F-5 NO.66 SEC.2 NAN-KAN RD ., LUCHU ,

TAOYUAN, TAIWAN

Email: server@ceramate.com.tw

Tel:886-3-3214525

Http: www.ceramate.com.tw

Fax:886-3-3521052

Page 4 of 11

Rev 1.0 Apr.19,2004

Figure 1. Representative Block Diagram

Figure 2. Timing Diagram

6

5

4

Deadtime

Control

Oscillator

0.12V

0.7V

0.7mA

+

1

-

-

+

-

+

+

2

-

D

Q

Ck

-

+

+

-

3.5V

4.9V

13

Reference

Regulator

Q1

Q2

8

9

11

10

12

12

3

15

16

14

7

Error Amp

1

Feedback PWM

Comparator Input

Ref.

Output

Gnd

UV

Lockout

Flip-

Flop

Output Control

Error Amp

2

Deadtime

Comparator

PWM

Comparator

Q

Feedback/PWM Comp.

Deadtime Control

Flip-Flop

Clock Input

Flip-Flop

Q

Flip-Flop

Q

Output Q1

Emitter

Output Q2

Emitter

Output

Control

This device contains 46 active transistors.