TS3404

1-5

2003/12 rev. A

TS3404

PWM Buck Controller

Pin assignment:

1. Out

2. Vcc

3. Comp.

4. FB

5. SCP

6. SS

7. CT

8.

Gnd

Supply Voltage Range 3.6V to 27V

Output Driving Current 200mA

Oscillator Frequency up to 300KHz

General Description

The TS3404 integrates Pulse Width Modulation (PWM) control circuit into a single chip, and makes simple work out of

implementing a complete control and protection scheme for a DC-DC step-down converter. The TS3404 provides simple

feedback loop compensation, 1.25V reference output, error amplifier, adjustable oscillator, soft start, under voltage lock

out (UVLO), short circuit protection(SCP) circuitry, and push pull output circuit.

The TS3404 is design for adjustable switching frequency by trimming time capacitor (CT), during low supply voltage

situation, the under voltage lock out (UVLO) makes sure that the output are off until the internal circuit operates normally.

The TS3404 is offered in DIP-8 and SOP-8 package.

Features

PWM buck control circuit

Operating voltage can be up to 27V

Under voltage lock out (UVLO) protection

Soft start (SS) circuit

Short circuit Protection (SCP)

Variable oscillator frequency 300KHz (max)

1.25V voltage reference Output

Pin Descriptions

Name

Description

Output

PWM Output

Vcc

Supply Voltage

Comp.

Feedback Loop Compensation

FB

Voltage Feedback

SCP

Short Circuit Protection

SS

Soft Start

CT

Timing Capacitor

Gnd

Ground

Applications

LCD Monitor

xD-ROM, xDSL product

DC to DC converters in computers

Backlight inverter

Ordering Information

Part No.

Operating Temp.

(Ambient)

Package

TS3404CS

SOP-8

TS3404CD

-20 ~ +85

DIP-8

Absolute Maximum Rating

Supply Voltage

28

V

Amplifier Input Voltage

20

V

Collector Output Voltage

Vcc~1.0V

V

Source Current

200

mA

Sink Current

200

mA

Operating Junction Temperature Range

-20 ~ +150

Storage Temperature Range

-65 ~ +150

Lead Temperature 1.6mm(1/16”) from case for 10Sec.

260