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POWER MANAGEMENT

Synchronous Buck Converter

with Programmable Output

SC190

The SC190 is a synchronous step-down converter with

integrated power devices and an integrated front-end

LDO to minimize input supply ripple. Output voltage is

programmable using two control bits, eliminating the need

for feedback resistors tied to the output. The device is

offered in four distinct variants with each variant providing

four fixed output voltage options to choose from.

The front-end LDO can be bypassed externally to maximize

efficiency. A second LDO is switched in place of the

switching regulator for low current operation to further

improve efficiency and reduce noise.

The SC190’s flexible clocking scheme allows it to be

synchronized to an external oscillator or controlled by the

internal oscillator. The 1MHz switching frequency allows

the use of small inductors and capacitors.

The internal MOSFET switches provide peak current

greater than 500mA to achieve a DC output of at least

300mA. Shutdown current is typically 0.1µA.

The SC190 has four different variants with four voltage

settings each. It is designed for single-cell Li-ion battery

applications, but also performs well in fixed 3.3V and 5V

applications.

Regulator or Linear Regulator

Regulator for Maximum Efficiency

1.5MHz Clocked Operation

SC190

4.7µF

4.7µF

4.7µH

VIN

VOUT

VIN

EN

SYNC/PWM

VID0

VID1

MODE

LX

VOUT

BP

GND

CIN

CBP

COUT

LOUT

4.7µF

Description

June 30, 2005

Applications

Features

Typical Application Circuit

Features