AP1503

300Khz, 2.5A PWM Buck DC/DC Converter

This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of

this product. No rights under any patent accompany the sale of the product.

Rev 1.0 Sep. 29, 2004

1/5

Features

- Output voltage: 3.3V

- 300KHz +15% fixed switching frequency

- Voltage mode non-synchronous PWM control

- Thermal-shutdown and current-limit protection

- ON/OFF shutdown control input

- Operating voltage can be up to 22V

- Output load current: 2.5A

- SOP-7L packages

- Low power standby mode

- Built-in switching transistor on chip

Applications

- Simple High-efficiency step-down regulator

- On-card switching regulators

- Positive to negative converter

- DSL Modems

- Portable Computers

- Regulated Wall Adapters

- Distributed Power

General Description

The AP1503 series are monolithic ICs designed for

step-down DC/DC converters, and own the ability

of driving a 2.5A load without additional transistor

components. Due to reducing the number of

external component, the board space can be saved

easily. The external shutdown function can be

controlled by logic level and then come into standby

mode. The external compensation makes feedback

control have good line and load regulation.

Regarding protected function, thermal shutdown is

to prevent over temperature operating from damage,

and current limit is against over current operating of

the output switch. The AP1503 series operates at a

switching frequency of 300KHz thus allowing

smaller sized filter components than what would be

needed with lower frequency switching regulators.

Other features include a guaranteed +2% tolerance

on output voltage under specified input voltage and

output load conditions, and +15% on the oscillator

frequency. The output version included fixed 3.3V,

5V. The packages are available in a standard

SOP-7 lead package.

Pin Assignment

SOP7 with Heat Sink

VB

VIN

COMP

SD

FB

GND

VO

7

6

5

2

3

4

1

Pin Descriptions

Name

Description

Operating voltage input

VB

Boost pin

SD

ON/OFF Shutdown

FB

Output voltage feedback control

COMP

Compensation pin

GND

Ground

VO

Switching output