POWER MANAGEMENT



SC632A

1MHz Fixed 5.0V Output

Charge Pump Regulator

Features

Input voltage range — 2.95V to 5.5V

V

Continuous output current — 275mA

Peak output current — 400mA

Three charge pump modes — x, .5x and 2x

Output ripple voltage — 50mV

Short circuit, over-voltage, and over-temperature

protection

Soft-start functionality

Shutdown current — 0.µA, typical

Ultra thin package — 2 x 2 x 0.6 (mm)

Lead-free and halogen-free

WEEE and RoHS compliant

Applications

Mobile phones

Tablets

USB On-The-Go

Multi-LED backlit LCDs

Compact flash/CF+ products

Digital video cameras

DVI/HDMI ports

Wi-Fi base stations

Modems

Set-top boxes

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Description

The SC632A is a high-current voltage regulator using

Semtech’s proprietary low-noise charge pump technol-

ogy. The charge pump provides a low EMI solution

compared to inductive boost regulators. Performance is

optimized for use in single Li-Ion battery cell applications.

The regulator provides the performance of a linear, low

drop-out (LDO) voltage regulator when the input is greater

than 5.0V. Unlike an LDO, drop-out is avoided when the

input is less than 5.0V. Instead, a charge pump is activated

to provide voltage boost and the head-room needed for

voltage regulation.

The SC632A’s charge pump has three modes of operation:

2x, .5x, and x modes. 2x and .5x are voltage boost

modes that deliver current to the load in each of two

phases. The x mode turns off the charge pump, deliver-

ing current through an LDO. Hysteresis is provided to

prevent chatter between charge pump modes. When

active, the charge pump provides low-ripple operation at

MHz. Typically the output ripple is 50mVpp at the

maximum continuous current rating of 275mA.

A small 2.2µF capacitor is recommended for all four capaci-

tors. The full rated output current is provided when 2.2µF

is used for both bucket capacitors. At the output, a 2.2µF

capacitor decouples the load and provides smoothing for

mode transitions, while another 2.2µF is used to decouple

the input.

SC632A

OUT

C1+

IN

GND

EN

C1-

C2+

C2-

2.2µF

2.2µF

2.2µF

2.2µF

Chip

enable

Typical Application Circuit

Revision .0

US Patent: 7,808,220

© 20 Semtech Corporation