POWER MANAGEMENT

1

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SC1408

Low Voltage, Boost

DC-DC Controller

Features

Applications

Revision: November 23, 2005

Typical Application Circuit

Description

The SC1408 is a low voltage boost controller that

operates from a 1.8V to 16.5V input range. The SC1408

was designed for two cell Alkaline or single cell Lithium

Ion

battery

applications.

With

the

proper

external components it can be used as a boost converter

or a buck/boost converter. A Shutdown pin allows the

user to turn the controller off, reducing supply current to

less than 2µA typical. Output voltage can be preset to 5V

or is adjustable from 3V to 16.5V with a resistor divider.

The controller changes frequency in light load conditions

to improve efficiency.

1.8V to 16.5V input range

Preset (5V) or adjustable output

Ground referenced current limit

On chip precision reference

Up to 300kHz switching frequency

10µA max shutdown current

Industrial temperature range

SO-8 and MSOP-8 packages. Lead free packages

available are fully WEEE and RoHS compliant

PDA Power supplies

Battery powered applications

Positive LCD Bias generator

Portable communications (cellular phones)

Peripheral card supplies

Industrial power supplies

Vin (1.8V to 16.5V)

Vout (3V to 16.5V)

U1

SC1408

8

1

2

3

4

5

6

7

ISENSE

GATE

BST

FB

SHDN

REF

AGND

GND

L1

R2

Q1

D1

+

C1

R4

R3

+

C2

C3