LTC1155

1

1155fb

TYPICAL APPLICATION

FEATURES

DESCRIPTION

Dual High Side

Micropower MOSFET Driver

The LTC®1155 dual high side gate driver allows using low

cost N-channel FETs for high side switching applications.

An internal charge pump boosts the gate above the posi-

tive rail, fully enhancing an N-channel MOSFET with no

external components. Micropower operation, with 8µA

standby current and 85µA operating current, allows use

in virtually all systems with maximum efficiency.

Included on-chip is overcurrent sensing to provide au-

tomatic shutdown in case of short circuits. A time delay

can be added in series with the current sense to prevent

false triggering on high in-rush loads such as capacitors

and incandescent lamps.

TheLTC1155operatesoffofa4.5Vto18Vsupplyinputand

safely drives the gates of virtually all FETs. The LTC1155

is well suited for low voltage (battery-powered) applica-

tions, particularly where micropower “sleep” operation

is required.

The LTC1155 is available in both 8-pin PDIP and 8-pin

SO packages.

APPLICATIONS

n

Fully Enhances N-Channel Power MOSFETs

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8µA Standby Current

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85µA ON Current

n

Short-Circuit Protection

n

Wide Power Supply Range: 4.5V to 18V

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Controlled Switching ON and OFF Times

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No External Charge Pump Components

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Replaces P-Channel High Side MOSFETs

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Compatible with Standard Logic Families

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Available in 8-Pin SO Package

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Laptop Power Bus Switching

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SCSI Termination Power Switching

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Cellular Phone Power Management

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P-Channel Switch Replacement

n

Relay and Solenoid Drivers

n

Low Frequency Half H-Bridge

n

Motor Speed and Torque Control

L

, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear

Technology Corporation. All other trademarks are the property of their respective owners.

1155 TA01

0.02

0.1µF

10µF

5A

MAX

100k

POWER BUS

µP

SYSTEM

DISK

DRIVE

DISPLAY

PRINTER,

ETC.

LTC1155

TTL, CMOS INPUT

TTL, CMOS INPUT

GND

GND

IN1

IN2

G2

DS2

DS1

G1

0.1µF

0.02

100k

*SURFACE MOUNT

*IRLR034

5A

MAX

*IRLR034

+

OUTPUT CURRENT (A)

0

0.00

0.05

0.10

0.15

0.20

0.25

1

2

3

1155 TA02

Switch Voltage Drop

Laptop Computer Power Bus Switch with Short-Circuit Protection