POWER MANAGEMENT

1

www.semtech.com

SC1452

Dual 150mA LDO Regulator

with Programmable Reset

Features

Applications

Revision: September 20, 2006

Typical Application Circuit

Description

The SC1452 is a state of the art device intended to

provide maximum performance and flexibility in battery

operated systems. It has been designed specifically to

fully support a single Li-Ion battery and its external charger

voltages.

The SC1452 contains two independently enabled, ultra

low dropout voltage regulators (ULDOs). It operates from

an input voltage range of 2.25V to 6.5V, and a wide

variety of output voltage options are available which are

designed to provide an initial tolerance of ±1% and ±2%

over temperature.

Each regulator has an associated active-low reset signal

which is asserted when the voltage output declines

below the preset threshold. Once the output recovers,

the reset continues to be asserted (delayed) for a

predetermined time, 50ms for reset A and 150ms for

reset B. In the case of regulator B, the delay time may be

reduced by the addition of an external capacitor.

The SC1452 has a bypass pin to enable the user to

capacitively decouple the bandgap reference for very low

output noise (down to 50µVrms).

The devices utilize CMOS technology to achieve very low

operating currents (typically 130uA with both

outputs supplying 150mA). The dropout voltage is

typically 155mV at 150mA, helping to prolong battery

life. In addition, the devices are guaranteed to provide

400mA of peak current for applications which require

high initial inrush current. They have been designed to

be used with low ESR ceramic capacitors to save cost

and PCB area.

The SC1452 comes in the low profile 10-lead MSOP

package.

Up to 150mA per regulator output

outputs at 150mA)

Low dropout voltage

Wide selection of output voltages

Stable operation with ceramic caps

Tight load and line regulation

Current and thermal limiting

Reverse input polarity protection

Logic controlled enable

Active low resets valid for V

Programmable reset

Full industrial temperature range

10-Pin MSOP package. Also available in Lead-free,

fully WEEE and RoHS compliant

Cellular telephones

Palmtop/Laptop computers

Battery-powered equipment

Bar code scanners

SMPS post regulator/dc to dc modules

High efficiency linear power supplies

DSP supplies

3.3V IN

ENABLE OUTPUT A

ENABLE OUTPUT B

RESET B

RESET A

2.5V OUT

3.0V OUT

U1

SC1452FIMS

1

2

3

4

5

6

7

8

9

10

OUTA

OUTB

GND

RSTA

RSTB

DLYB

ENB

BYP

ENA

IN

COUTA

1uF

CBYP

10nF

CDLYB

10nF

CIN

1uF

COUTB

1uF