AP1604

PWM/PFM Dual Mode Step-down 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.1.1 Jun. 27, 2005

1/7

Features

- Oscillator frequency: 600KHz (Typ.)

- Internal reference: 1.0V (Typ.)

- High efficiency: 93% (Typ .)

- Soft-start time set-up externally type possible

- Current limit and thermal shutdown protection

- Pb-Free Package: SOT23-5, SON-6(3

×3×0.8mm)

Applications

● Electronic Information Organizers

● Palmtops

● Cellular and portable phones

● Portable Audio Systems

● Various Multi-function Power Supplies

General Descriptions

The AP1604 series are multi-functional step-down

DC/DC converters with built-in speed, low ON

resistance drivers. It is capable to deliver more than

800mA output current with external coil, diode and

capacitor.

Output voltage is set-up by the external resistors. (±

2.5% accuracy). The 600KHz AP1604 that can

work out with small value external components

comes out more compact board.

The device switches to and works under PFM mode

with light loads. It keeps at high efficiency for both

light loads and large output current.

AP1604 can be soft-start with a proper capacitor

connected between CE/SS pin and ground. The

stand-by current is less than 2uA when CE/SS pin

is at “LOW” status. The device is forced to switch

off as the voltage at that pin is lower than the

stipulated voltage.

Pin Assignment

1

3

2

5

4

CE/SS

V

OUT

V

CC

GND

SOT23-5

FB

(Top View)

AP1604A

SON-6

1

2

3

4

5

6

GND

CE

FB

V

OUT

V

CC

SV

CC

Pin Descriptions

Pin Name

Function

Output Voltage

Input Supply

GND

Ground

CE/SS

Chip Enable / Soft Start

FB

Feedback pin

Signal Power for SON only