LM3352

Regulated 200 mA Buck-Boost Switched Capacitor

DC/DC Converter

General Description

The LM3352 is a CMOS switched capacitor DC/DC con-

verter that produces a regulated output voltage by automati-

cally stepping up (boost) or stepping down (buck) the input

voltage. It accepts an input voltage between 2.5V and 5.5V.

The LM3352 is available in three standard output voltage

versions: 2.5V, 3.0V and 3.3V. If other output voltage options

between 1.8V and 4.0V are desired, please contact your Na-

tional Semiconductor representative.

The LM3352’s proprietary buck-boost architecture enables

up to 200 mA of load current at an average efficiency greater

than 80%. Typical operating current is only 400 µA and the

typical shutdown current is only 2.5 µA.

The LM3352 is available in a 16-pin TSSOP package. This

package has a maximum height of only 1.1 mm.

The high efficiency of the LM3352, low operating and shut-

down currents, small package size, and the small size of the

overall solution make this device ideal for battery powered,

portable, and hand-held applications.

Features

n Standard output voltage options: 2.5V, 3.0V and 3.3V

n Custom output voltages available from 1.8V to 4.0V in

100 mV increments

n 2.5V to 5.5V input voltage

n Up to 200 mA output current

n Uses few, low-cost external components

n Very small solution size

n 400 µA typical operating current

n 2.5 µA typical shutdown current

n 1 MHz switching frequency (typical)

n Architecture and control methods provide high load

current and good efficiency

n TSSOP-16 package

n Over-temperature protection

Applications

n 1-cell Lilon battery-operated equipment including PDAs,

hand-held PCs, cellular phones

n Flat panel displays

n Hand-held instruments

n NiCd, NiMH, or alkaline battery powered systems

n 3.3V to 2.5V and 5.0V to 3.3V conversion

Typical Operating Circuit

DS101037-1

September 1999

© 1999 National Semiconductor Corporation

DS101037

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