POWER LOSS (mW)
LTC3632
High Efficiency, High Voltage
20mA Synchronous
Step-Down Converter
FEATURES DESCRIPTION
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Wide Input Voltage Range: Operation from The LTC 3632 is a high efficiency, high voltage step-down
4.5V to 50V DC/DC converter with internal high side and synchronous
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Overvoltage Lockout Provides Protection Up to 60V power switches that draws only 12A typical DC sup-
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Internal High Side and Low Side Power Switches ply current at no load while maintaining output voltage
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No Compensation Required regulation.
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20mA Output Current
The LTC3632 can supply up to 20mA load current and
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Low Dropout Operation: 100% Duty Cycle
features a programmable peak current limit that provides
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Low Quiescent Current: 12A
a simple method for optimizing efficiency in lower current
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Wide Output Voltage Range: 0.8V to V
IN
applications. The LTC3632s combination of Burst Mode
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0.8V 1% Feedback Voltage Reference
operation, integrated power switches, low quiescent cur-
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Adjustable Peak Current Limit
rent, and programmable peak current limit provides high
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Internal and External Soft-Start
efficiency over a broad range of load currents.
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Precise RUN Pin Threshold with Adjustable
With its wide 4.5V to 50V input range and internal
Hysteresis
n overvoltage monitor capable of protecting the part through
Few External Components Required
n 60V surges, the LTC3632 is a robust converter suited for
Low Profile (0.75mm) 3mm 3mm DFN and
regulating a wide variety of power sources. Additionally,
Thermally Enhanced MS8E Packages
the LTC3632 includes a precise run threshold and soft-start
feature to guarantee that the power system start-up is
APPLICATIONS
well-controlled in any environment.
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4mA to 20mA Current Loops
The LTC3632 is available in the thermally enhanced
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Industrial Control Supplies
3mm 3mm DFN and MS8E packages.
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Distributed Power Systems
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L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks
Portable Instruments
and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the
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Battery-Operated Devices
property of their respective owners.
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Automotive Power Systems
Efficiency and Power Loss vs Load Current
TYPICAL APPLICATION
100
1000
5V, 20mA Step-Down Converter 90
EFFICIENCY
80
1mH
V
OUT
V
IN
V SW 5V
IN
5V TO 50V
70 100
20mA
LTC3632
1F 10F
1.47M
RUN
60
V
HYST
FB
50 10
I SS
SET
280k
POWER LOSS
GND
40
3632 TA01a
30 1
V = 10V
IN
V = 48V
IN
20
0.1 1 10
LOAD CURRENT (mA) 3632 TA01b
3632fc
1
EFFICIENCY (%)LTC3632
ABSOLUTE MAXIMUM RATINGS (Note 1)
V Supply Voltage ..................................... 0.3V to 60V Storage Temperature Range ................... 65C to 150C
IN
SW Voltage (DC) ............................0.3V to (V + 0.3V) Lead Temperature (Soldering, 10 sec)
IN
RUN Voltage .............................................. 0.3V to 60V MS8E ................................................................ 300C
V , HYST, I , SS Voltages ........................ 0.3V to 6V
FB SET
Operating Junction Temperature Range
(Note 2) .................................................. 40C to 125C
PIN CONFIGURATION
TOP VIEW
TOP VIEW
SW 1 8 GND
SW 1 8 GND
V 2 7 HYST
IN
V 2 9 7 HYST 9
IN
GND GND
I 3 6 V I V
SET FB 3 6
SET FB
5 RUN
SS 4
SS RUN
4 5
MS8E PACKAGE
8-LEAD PLASTIC MSOP
DD PACKAGE
T = 125C, = 40C/W, = 5-10C/W
JMAX JA JC
8-LEAD (3mm 3mm) PLASTIC DFN
EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB
T = 125C, = 43C/W, = 3C/W
JMAX JA JC
EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC3632EMS8E#PBF LTC3632EMS8E#TRPBF LTFFZ 8-Lead Plastic MSOP 40C to 125C
LTC3632IMS8E#PBF LTC3632IMS8E#TRPBF LTFFZ 8-Lead Plastic MSOP 40C to 125C
LTC3632EDD#PBF LTC3632EDD#TRPBF LFGB 8-Lead (3mm 3mm) Plastic DFN 40C to 125C
LTC3632IDD#PBF LTC3632IDD#TRPBF LFGB 40C to 125C
8-Lead (3mm 3mm) Plastic DFN
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to: