LT3502/LT3502A
1.1MHz/2.2MHz, 500mA
Step-Down Regulators in
2mm × 2mm DFN and MS10
DESCRIPTION
FEATURES
The LT®3502/LT3502A are current mode PWM step-down
DC/DC converters with an internal 500mA power switch,
in tiny 8-lead 2mm × 2mm DFN and 10-lead MS10
packages.Thewideinputvoltagerangeof3Vto40Vmakes
the LT3502/LT3502A suitable for regulating power from a
wide variety of sources, including 24V industrial supplies
and automotive batteries. Its high operating frequency
allows the use of tiny, low cost inductors and capacitors,
resulting in a very small solution. Constant frequency
abovetheAMbandavoidsinterferingwithradioreception,
making the LT3502A particularly suitable for automotive
applications.
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3V to 40V Input Voltage Range
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500mA Output Current
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Switching Frequency: 2.2MHz (LT3502A),
1.1MHz (LT3502)
800mV Feedback Voltage
Short-Circuit Robust
Soft-Start
Low Shutdown Current: <2μA
Internally Compensated
Internal Boost Diode
Thermally Enhanced 2mm × 2mm 8-Lead DFN
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and 10-lead MS10 Package
Cycle-by-cycle current limit and frequency foldback
provide protection against shorted outputs. Soft-start
and frequency foldback eliminates input current surge
duringstart-up. DAcurrentsenseprovidesfurtherprotec-
tion in fault conditions. An internal boost diode reduces
component count.
APPLICATIONS
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Automotive Systems
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Battery-Powered Equipment
Wall Transformer Regulation
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Distributed Supply Regulation
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
LT3502A 12VIN Efficiency
3.3V Step-Down Converter
90
80
BD
5V
3.3V
OUT
V
OUT
IN
V
BOOST
SW
IN
70
60
50
40
30
20
10
4.7V TO 40V
1μF
0.1μF
6.8μH
31.6k
V
OUT
3.3V
500mA
LT3502A
DA
FB
SHDN
OFF ON
GND
10k
10μF
3502 TA01a
0
0
0.4
0.5
0.1
0.2
0.3
LOAD CURRENT (A)
3502 TA01b
3502fc
1