LT3502/LT3502A
1.1MHz/2.2MHz, 500mA
Step-Down Regulators in
2mm × 2mm DFN and MS10
Description
Features
3V to 40V Input Voltage Range
n 500mA Output Current
n Switching Frequency: 2.2MHz (LT3502A),
1.1MHz (LT3502)
n 800mV Feedback Voltage
n Short-Circuit Robust
n Soft-Start
n Low Shutdown Current: <2µA
n Internally Compensated
n Internal Boost Diode
n Thermally Enhanced 2mm × 2mm 8-Lead DFN
and 10-Lead MS10 Package
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. The wide input voltage range of 3V to 40V makes
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
above the AM band avoids interfering with radio reception,
making the LT3502A particularly suitable for automotive
applications.
n
Cycle-by-cycle current limit and frequency foldback
provide protection against shorted outputs. Soft-start
and frequency foldback eliminates input current surge
during start-up. DA current sense provides further protection in fault conditions. An internal boost diode reduces
component count.
Applications
n
n
n
n
Automotive Systems
Battery-Powered Equipment
Wall Transformer Regulation
Distributed Supply Regulation
L, LT, LTC, LTM, Linear Technology and the Linear logo 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
BOOST
VIN
1µF
SW
0.1µF 6.8µH
LT3502A
VOUT
3.3V
500mA
DA
OFF ON
SHDN
GND
31.6k
FB
10k
5VOUT
70
10µF
EFFICIENCY (%)
VIN
4.7V TO 40V
3.3VOUT
60
50
40
30
20
10
3502 TA01a
0
0
0.1
0.3
0.2
LOAD CURRENT (A)
0.4
0.5
3502 TA01b
3502fd
1
