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LT1161

Quad Protected High-Side

MOSFET Driver

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Fully Enhances N-Channel MOSFET Switches

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8V to 48V Power Supply Range

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Protected from – 15V to 60V Supply Transients

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Individual Short-Circuit Protection

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Individual Automatic Restart Timers

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Programmable Current Limit, Delay Time, and

Auto-Restart Period

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Voltage-Limited Gate Drive

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Defaults to OFF State with Open Input

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Flowthrough Input to Output Pinout

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Available in 20-Lead DIP or SOL Package

The LT1161 is a quad high-side gate driver allowing the

use of low cost N-channel power MOSFETs for high-side

switching applications. It has four independent switch

channels, each containing a completely self-contained

charge pump to fully enhance an N-channel MOSFET

switch with no external components.

Also included in each switch channel is a drain sense

comparator that is used to sense switch current. When a

preset current level is exceeded, the switch is turned off.

The switch remains off for a period of time set by an

external timing capacitor and then automatically attempts

to restart. If the fault is still present, this cycle repeats until

the fault is removed, thus protecting the MOSFET.

The LT1161 has been specifically designed for harsh

operating environments such as industrial, avionics, and

automotive applications where poor supply regulation

and/or transients may be present. The device will not

sustain damage from supply voltages of –15V to 60V.

FEATURES

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Industrial Control

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Avionics Systems

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Automotive Switches

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Stepper Motor and DC Motor Control

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Electronic Circuit Breaker

+

0.1

µF

0.1

µF

0.1

µF

0.1

µF

0.01

Ω

IRFZ34

24V

INPUTS

1161 F01

IRFZ34

IRFZ34

IRFZ34

0.01

Ω

0.01

Ω

0.01

Ω

LOAD

#1

50

µF

50V

LOAD

#2

LOAD

#3

LOAD

#4

DS1

G1

DS2

G2

DS3

G3

DS4

G4

T1

T2

T3

T4

GND

GND

IN1

IN2

IN3

IN4

LT1161

Switch Drop vs Load Current

LOAD CURRENT (A)

0

0.50

0.45

0.40

0.35

0.30

0.25

0.20

0.15

0.10

0.05

0

4

1161 TA01

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2

3

5

Figure 1. Protected Quad High-Side Switch