LT1161
Quad Protected High-Side
MOSFET Driver
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FEATURES
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DESCRIPTIO
8V to 48V Power Supply Range
Protected from – 15V to 60V Supply Transients
Fully Enhances N-Channel MOSFET Switches
Individual Short-Circuit Protection
Individual Automatic Restart Timers
Programmable Current Limit, Delay Time, and
Auto-Restart Period
Voltage-Limited Gate Drive
Defaults to OFF State with Open Input
Flowthrough Input to Output Pinout
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.
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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.
Industrial Control
Avionics Systems
Automotive Switches
Stepper Motor and DC Motor Control
Electronic Circuit Breaker
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.
APPLICATIO S
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, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
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TYPICAL APPLICATIO
24V
+
0.1µF
0.1µF
0.1µF
INPUTS
T1
DS1
RS
0.01Ω
T2
G1
Switch Drop vs Load Current
50µF
50V
IRFZ34
V+
V+
0.45
DS2
T3
T4
IN1
IN2
IN3
IN4
GND
GND
0.50
LT1161
G2
0.01Ω
LOAD
#1
IRFZ34
DS3
0.01Ω
G3
IRFZ34
DS4
0.01Ω
G4
LOAD
#2
IRFZ34
0.40
TOTAL DROP (V)
CT
0.1µF
0.35
0.30
0.25
0.20
0.15
LOAD
#3
0.10
0.05
0
LOAD
#4
0
1
3
2
LOAD CURRENT (A)
4
5
1161 TA01
1161 F01
Figure 1. Protected Quad High-Side Switch
1161fa
1
