LM2735 Datasheet, PDF (1/38 Pages) National Semiconductor (TI) – 520kHz/1.6MHz - Space-Efficient Boost and SEPIC DC-DC Regulator

August 2007
LM2735
520kHz/1.6MHz – Space-Efficient Boost and SEPIC DC-DC
Regulator
General Description
The LM2735 is an easy-to-use, space-efficient 2.1A low-side
switch regulator ideal for Boost and SEPIC DC-DC regulation.
It provides all the active functions to provide local DC/DC
conversion with fast-transient response and accurate regula-
tion in the smallest PCB area. Switching frequency is inter-
nally set to either 520kHz or 1.6MHz, allowing the use of
extremely small surface mount inductor and chip capacitors
while providing efficiencies up to 90%. Current-mode control
and internal compensation provide ease-of-use, minimal
component count, and high-performance regulation over a
wide range of operating conditions. External shutdown fea-
tures an ultra-low standby current of 80 nA ideal for portable
applications. Tiny SOT23-5, LLP-6, and eMSOP-8 packages
provide space-savings. Additional features include internal
soft-start, circuitry to reduce inrush current, pulse-by-pulse
current limit, and thermal shutdown.
Features
■ ^{Input voltage range 2.7V to 5.5V}
■ ^{Output voltage range 3V to 24V}
■ ^{2.1A switch current over full temperature range}
■ ^{Current-Mode control}
■ ^{Logic high enable pin}
■ ^{Ultra low standby current of 80 nA in shutdown}
■ ^{170 mΩ NMOS switch}
■ ^{±2% feedback voltage accuracy}
■ ^{Ease-of-use, small total solution size}
Internal soft-start
Internal compensation
Two switching frequencies
520 kHz (LM2735-Y)
1.6 MHz (LM2735-X)
Uses small surface mount inductors and chip capacitors
Tiny SOT23-5, LLP-6, and eMSOP-8 packages
Applications
■ ^{LCD Display Backlighting For Portable Applications}
■ ^{OLED Panel Power Supply}
■ ^{USB Powered Devices}
■ ^{Digital Still and Video Cameras}
■ ^{White LED Current Source}
Typical Boost Application Circuit
20215801
20215815
Efficiency vs Load Current V_O = 12V
© 2007 National Semiconductor Corporation 202158
www.national.com