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LTC1157

3.3V Dual Micropower

High-Side/Low-Side MOSFET Driver

The LTC1157 dual 3.3V micropower MOSFET gate driver

makes it possible to switch either supply or ground

(N-channel switches are required at 3.3V because P-

the gate drive voltage 5.4V above the positive rail (8.7V

above ground), fully enhancing a logic level N-channel

switch for 3.3V high-side applications and a standard N-

channel switch for 3.3V low-side applications. The gate

drive voltage at 5V is typically 8.8V above supply (13.8V

above ground), so standard N-channel MOSFET switches

can be used for both high-side and low-side applications.

Micropower operation, with 3

µA standby current and

80

µA operating current, makes the LTC1157 well suited

for battery-powered applications.

The LTC1157 is available in both 8-pin DIP and SOIC.

S

FEATURE

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Allows Lowest Drop 3.3V Supply Switching

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Operates on 3.3V or 5V Nominal Supplies

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3 Microamps Standby Current

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80 Microamps ON Current

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Drives Low Cost N-Channel Power MOSFETs

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No External Charge Pump Components

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Controlled Switching ON and OFF Times

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Compatible with 3.3V and 5V Logic Families

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Available in 8-Pin SOIC

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APPLICATI

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Notebook Computer Power Management

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Palmtop Computer Power Management

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P-Channel Switch Replacement

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Battery Charging and Management

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Mixed 5V and 3.3V Supply Switching

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Stepper Motor and DC Motor Control

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Cellular Telephones and Beepers

DESCRIPTIO

APPLICATI

TYPICAL

+

GND

G2

G1

IN2

IN1

LTC1157

3.3V

LOGIC

(8.7V)

(8.7V)

IRLR024

IRLR024

3.3V

LOAD

3.3V

LOAD

10

µF

3.3V

LTC1157 • TA01

Ultra Low Voltage Drop 3.3V Dual High-Side Switch

Gate Voltage Above Supply

SUPPLY VOLTAGE (V)

2.0

0

2

4

6

8

3.0

4.0

5.0

6.0

LTC1157 • TA02

10

12

2.5

3.5

4.5

5.5