AP1623

PWM Control Step-Down Switching Regulator-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. 0.1 Feb 10, 2004

1/6

Features

- Low current consumption:

In operation: 60µA max.

Power off: 0.5µA max.

- Input voltage: 2.5V to 16V.

- Output voltage: 1.8V & Adjustable to 6V.

- Duty ratio: 0% to 100% PWM control

- Oscillation frequency: 180KHz typ.

- Soft-start function: 8ms typ.

- With a power-off function.

- Built-in internal SW P-channel MOS

- SOP-8L Package.

Applications

- On-board power supplies of battery devices for

portable telephones, electronic notebooks, PDA,

and other hand-held sets.

- Power supplies for audio equipment, including

portable CD players and headphone stereo

equipment.

- Fixed voltage power supply for cameras, video

equipment and communications equipment.

- Power supplies for microcomputers.

- Conversion from four Ni-H or Ni-Cd cells or two

lithium-ion cells to 3.3V/3V.

- Conversion of AC adapter input to 5V/3V.

General Description

AP1623 consists of CMOS step-down switching

regulator-controllers with PWM control. These devices

include a reference voltage source, oscillation circuit,

error amplifier, internal PMOS and etc.

AP1623 provides low-ripple power, high efficiency,

and excellent transient characteristics. The PWM

control circuit is able to very the duty ratio linearly

from 0 up to 100. This converter also contains an

error amplifier circuit as well as a soft-start circuit that

prevent s overshoot at startup.

With the addition of an internal P-channel Power MOS,

a coil, capacitors, and a diode connected externally,

these ICs can function as step-down switching

regulators. They serve as ideal power supply units for

portable devices when coupled with the SOP–8L

mini-package, providing such outstanding features as

low current consumption. Since this converter can

accommodate an input voltage of up to 16V, it is also

ideal when operating via an AC adapter.

Pin Assignments

1

2

3

4

8

7

6

5

SW

AP1623

SW

ON/OFF

Vss

Vss

Pin Descriptions

Name

Pin

Description

1

Output voltage monitoring pin

ON/OFF

2

Power-off pin

H: Normal operation

(Step-down operation)

L: Step-down operation

stopped

(All circuits deactivated)

3

IC signal power supply pin

4

IC power supply pin

SW

5、6

Switch Pin. Connect external

inductor/diode here. Minimize

trace area at this pin to reduce

EMI.

7、8 GND Pin