LTC3631_15 Datasheet, PDF (1/22 Pages) Linear Technology – High Efficiency, High Voltage 100mA Synchronous Step-Down Converter

LTC3631
High Efficiency, High Voltage
100mA Synchronous
Step-Down Converter
Features
Description
n _{Wide Input Voltage Range: Operation from 4.5V to 45V}
n _{Overvoltage Lockout Provides Protection Up to 60V}
n _{Internal High Side and Low Side Power Switches}
n _{No Compensation Required}
n _{100mA Output Current}
n _{Low Dropout Operation: 100% Duty Cycle}
n _{Low Quiescent Current: 12µA}
n _{0.8V ±1% Feedback Voltage Reference}
n _{Adjustable Peak Current Limit}
n _{Internal and External Soft-Start}
n _{Precise RUN Pin Threshold with Adjustable}
Hysteresis
n _{3.3V, 5V and Adjustable Output Versions}
n _{Only Three External Components Required for Fixed}
Output Versions
n _{Low Profile (0.75mm) 3mm × 3mm DFN and}
Thermally-Enhanced MS8E Packages
Applications
n _{4mA to 20mA Current Loops}
n _{Industrial Control Supplies}
n _{Distributed Power Systems}
n _{Portable Instruments}
n _{Battery-Operated Devices}
n _{Automotive Power Systems}
The LTC^®3631 is a high voltage, high efficiency step-down
DC/DC converter with internal high side and synchronous
power switches that draws only 12μA typical DC supply
current at no load while maintaining output voltage
regulation.
The LTC3631 can supply up to 100mA load current and
features a programmable peak current limit that provides
a simple method for optimizing efficiency in lower current
applications. The LTC3631’s combination of Burst Mode^®
operation, integrated power switches, low quiescent cur-
rent, and programmable peak current limit provides high
efficiency over a broad range of load currents.
With its wide 4.5V to 45V input range and internal overvolt-
age monitor capable of protecting the part from 60V surges,
the LTC3631 is a robust converter suited for regulating a
wide variety of power sources. Additionally, the LTC3631
includes a precise run threshold and a soft‑start feature
to guarantee that power system start-up is well-controlled
in any environment.
The LTC3631 is available in the thermally enhanced
3mm × 3mm DFN and MS8E packages.
L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks
and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
Typical Application
5V, 100mA Step-Down Converter
V_IN
5V TO 45V
2.2µF
V_IN
SW
LTC3631-5
RUN
HYST
V_OUT
SS
I_SET
GND
100µH
3631 TA01a
V_OUT
5V
10µF ^100mA
Efficiency and Power Loss vs Load Current
100
90
EFFICIENCY
1000
80
70
100
60
POWER LOSS
50
10
40
30
20
0.1
V_IN = 12V ¹
V_IN = 36V
1
10
LOAD CURRENT (mA)
100
3631 TA01b
For more information www.linear.com/LTC3631
3631fe
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