TCM828/829-4 5/22/00

TCM828

TCM829

© 2001 Microchip Technology Inc.

DS21488A

Switched Capacitor Voltage Converters

FEATURES

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Charge Pump in 5-Pin SOT-23A Package

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>95% Voltage Conversion Efficiency

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Voltage Inversion and/or Doubling

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Low 50

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Operates from +1.5V to +5.5V

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Up to 25mA Output Current

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Only Two External Capacitors Required

APPLICATIONS

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LCD Panel Bias

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Cellular Phones

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Pagers

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PDAs, Portable Dataloggers

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Battery-Powered Devices

GENERAL DESCRIPTION

The TCM828/829 are CMOS “charge-pump” voltage

converters in ultra-small 5-Pin SOT-23A packages. They

invert and/or double an input voltage which can range from

+1.5V to +5.5V. Conversion efficiency is typically >95%.

Switching frequency is 12kHz for the TCM828 and 35kHz for

the TCM829.

External component requirement is only two capacitors

(3.3

µF nominal) for standard voltage inverter applications.

With a few additional components a positive doubler can

also be built. All other circuitry, including control, oscillator,

power MOSFETs are integrated on-chip. Supply current

is 50

µA (TCM828) and 115µA (TCM829).

The TCM828 and TCM829 are available in a 5-Pin

SOT-23A surface mount package.

TYPICAL OPERATING CIRCUIT

ORDERING INFORMATION

Part No.

Package

Temp. Range

TCM828ECT

5-Pin SOT-23A

– 40

°C to +85°C

TCM829ECT

5-Pin SOT-23A

– 40

°C to +85°C

NOTE: 5-Pin SOT-23A is equivalent to EIAJ SC-74A.

PIN CONFIGURATION

TCM828

TCM829

OUTPUT

INPUT

GND

OUT

C+

C–

OUT

TCM828ECT

TCM829ECT

1

2

3

5

GND

VIN

4

*5-Pin SOT-23A

NOTE: *5-Pin SOT-23A is equivalent to EIAJ SC-74A

Voltage Inverter