LTC3824
High Voltage Step-Down
Controller With 40µA
Quiescent Current
DESCRIPTION
The LTC®3824 is a step-down DC/DC controller designed
to drive an external P-channel MOSFET. With a wide input
range of 4V to 60V and a high voltage gate driver, the
LTC3824 is suitable for many industrial and automotive
highpowerapplications.Constantfrequencycurrentmode
operation provides excellent performance.
FEATURES
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Wide Input Range: 4V to 60V
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Current Mode Constant Frequency PWM
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Very Low Dropout Operation: 100% Duty Cycle
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Programmable Switching Frequency:
200kHz to 600kHz
Selectable High Efficient Burst Mode® Operation:
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40μA Quiescent Current
Easy Synchronization
8V, 2A Gate Drive (V > 10V) for Industrial High
The LTC3824 can be configured for Burst Mode operation.
Burst Mode operation enhances low current efficiency
(only 40μA quiescent current) and extends battery run
time. The switching frequency can be programmed up to
600kHz and is easily synchronizable.
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CC
Voltage P-channel MOSFET
Programmable Soft-Start
Programmable Current Limit
Available in a Small 10-Pin Thermally Enhanced
MSE Package
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Otherfeaturesincludecurrentlimit,soft-start,micropower
shutdown, and Burst Mode disable.
The LTC3824 is available in a 10-lead MSE power package.
APPLICATIONS
L, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners. Protected by U.S. Patents
including 5731964.
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Industrial and Automotive Power Supplies
Telecom Power Supplies
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Distributed Power Systems
TYPICAL APPLICATION
5V/2A Buck Converter
Efficiency and Power Loss vs Load Current
V
IN
5.5V TO 60V
100
2.5
2.0
1.5
1.0
C
CAP
C
+
IN
0.1μF
33μF
100V
V
V
= 12V
= 40V
IN
IN
CAP
EFFICIENCY
90
V
CC
R
S
0.025Ω
80
SENSE
GATE
LTC3824
70
R
SET
22μH
V
OUT
392k
5V
V
= 40V
IN
60
50
0.5
0
C
OUT 2A
GND
POWER LOSS
100μF
100pF
51Ω
V
= 12V
s2
IN
422k
10
100
LOAD CURRENT (mA)
1000 2000
SYNC/MODE
SS
V
FB
3824 TA01a
V
C
80.6k
0.1μF
10k
3.3nF
3824 TA01
3824fc
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