LT3502_15 Datasheet, PDF (1/24 Pages) Linear Technology – 1.1MHz/2.2MHz, 500mA Step-Down Regulators

Features
n _{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
Applications
n _{Automotive Systems}
n _{Battery-Powered Equipment}
n _{Wall Transformer Regulation}
n _{Distributed Supply Regulation}
LT3502/LT3502A
1.1MHz/2.2MHz, 500mA
Step-Down Regulators in
2mm × 2mm DFN and MS10
Description
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.
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 protec-
tion in fault conditions. An internal boost diode reduces
component count.
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
3.3V Step-Down Converter
V_IN
4.7V TO 40V
BD
V_IN
BOOST
1µF
SW
LT3502A
DA
OFF ON
SHDN
FB
GND
0.1µF _6.8µH
V_OUT
3.3V
500mA
31.6k
10k
10µF
3502 TA01a
LT3502A 12V_IN Efficiency
90
80
5V_OUT
3.3V_OUT
70
60
50
40
30
20
10
0
0
0.1
0.2
0.3
0.4
0.5
LOAD CURRENT (A)
3502 TA01b
3502fd
1