LTC3632_15 Datasheet, PDF (1/22 Pages) Linear Technology – High Efficiency, High Voltage 20mA Synchronous Step-Down Converter

LTC3632
High Efficiency, High Voltage
20mA Synchronous
Step-Down Converter
FEATURES
n _{Wide Input Voltage Range: Operation from}
4.5V to 50V
n _{Overvoltage Lockout Provides Protection Up to 60V}
n _{Internal High Side and Low Side Power Switches}
n _{No Compensation Required}
n _{20mA Output Current}
n _{Low Dropout Operation: 100% Duty Cycle}
n _{Low Quiescent Current: 12µA}
n _{Wide Output Voltage Range: 0.8V to VIN}
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 _{Few External Components Required}
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}
DESCRIPTION
The LTC^®3632 is a high efficiency, high voltage step-down
DC/DC converter with internal high side and synchronous
power switches that draws only 12μA typical DC sup-
ply current at no load while maintaining output voltage
regulation.
The LTC3632 can supply up to 20mA load current and
features a programmable peak current limit that provides
a simple method for optimizing efficiency in lower current
applications. The LTC3632’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 50V input range and internal
overvoltage monitor capable of protecting the part through
60V surges, the LTC3632 is a robust converter suited for
regulating a wide variety of power sources. Additionally,
the LTC3632 includes a precise run threshold and soft‑start
feature to guarantee that the power system start-up is
well-controlled in any environment.
The LTC3632 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
V_IN
5V TO 50V
1µF
5V, 20mA Step-Down Converter
1mH
V_IN
SW
LTC3632
RUN
HYST
V_FB
I_SET
SS
GND
1.47M
280k
3632 TA01a
V_OUT
5V
10µF ^20mA
Efficiency and Power Loss vs Load Current
100
90
EFFICIENCY
80
1000
70
100
60
50
10
POWER LOSS
40
30
20
0.1
V_IN = 10V ¹
V_IN = 48V
1
LOAD CURRENT (mA)
10
3632 TA01b
3632fc
1