AP1635

PWM/PFM DUAL MODE STEP-DOWN DC/DC

CONVERTER

AP1635 Rev. 3

1 of 7

OCTOBER 2006

www.diodes.com

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Oscillator frequency: 700KHz (Typ.)

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Internal reference: 1.0V (Typ.)

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High efficiency: 93% (Typ.)

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Current limit and thermal shutdown protection

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Pb-Free

Package: SOP-8L

The AP1635 series are multi-functional step-down DC/DC

converters with built-in speed, low ON resistance drivers. It is

capable to deliver more than 1.2A output current with external

coil, diode and capacitor.

Output voltage is set-up by the external resistors. (±2.5%

accuracy). The 700KHz AP1635 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.

AP1635 can be soft-start with a proper capacitor connected

between CE/SS pin and ground. The stand-by current is less

than 6uA 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.

( Top View )

1

2

3

4

8

7

6

5

FB

SW

SVcc

AP1635

SW

GND

GND

PVcc

CE/SS

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Electronic Information Organizers

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Palmtops

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Cellular and portable phones

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Portable Audio Systems

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Various Multi-function Power Supplies

Features

General Description

Pin Assignments

Pin Descriptions

Applications

Pin

Name

Pin

No.

Description

FB

1

Feedback pin

CE/SS

2

Chip Enable/ Soft Start:

H: Enable

L: Disable

SVcc

3

IC signal power supply pin, add a

20Ω resistor to PVcc and a 0.1µF

capacitor to GND.

PVcc

4

IC power supply pin

SW

5/6

Switch Pin. Connect external

inductor/diode here. Minimize trace

area at this pin to reduce EMI.

GND

7/8 GND Pin