LT3470HTS8 Datasheet, PDF (1/20 Pages) Linear Integrated Systems – Micropower Buck Regulator with Integrated Boost and Catch Diodes

LT3470
Features
Micropower Buck Regulator
with Integrated Boost and
Catch Diodes
Description
n _{Low Quiescent Current: 26µA at 12VIN to 3.3VOUT}
n _{Integrated Boost and Catch Diodes}
n _{Input Range: 4V to 40V}
n _{Low Output Ripple: <10mV}
n _{< 1µA in Shutdown Mode}
n _{Output Voltage: 1.25V to 16V}
n _{200mA Output Current}
n _{Hysteretic Mode Control}
– Low Ripple Burst Mode^® Operation at Light Loads
– Continuous Operation at Higher Loads
n _{Solution Size as Small as 50mm}²
n _{Low Profile (0.75mm) 3mm × 2mm Thermally}
Enhanced 8-Lead DD and 1mm ThinSOT Packages
Applications
n _{Automotive Battery Regulation}
n _{Power for Portable Products}
n _{Distributed Supply Regulation}
n _{Industrial Supplies}
n _{Wall Transformer Regulation}
The LT^®3470 is a micropower step-down DC/DC con-
verter that integrates a 300mA power switch, catch diode
and boost diode into low profile 3mm × 2mm DD and
ThinSOT™ packages. The LT3470 combines Burst Mode
and continuous operation to allow the use of tiny induc-
tor and capacitors while providing a low ripple output to
loads of up to 200mA.
With its wide input range of 4V to 40V, the LT3470 can
regulate a wide variety of power sources, from 2-cell Li‑Ion
batteries to unregulated wall transformers and lead-acid
batteries. Quiescent current in regulation is just 26µA in
a typical application while a zero current shutdown mode
disconnects the load from the input source, simplifying
power management in battery-powered systems. Fast
current limiting and hysteretic control protects the LT3470
and external components against shorted outputs, even
at 40V input.
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
Typical Application
V_IN
7V TO 40V
OFF ON
V_IN BOOST
LT3470
SHDN
SW
BIAS
2.2µF
FB
GND
0.22µF
33µH
22pF
604k
1%
200k
1%
3470 TA01a
V_OUT
5V
200mA
22µF
Efficiency and Power Loss vs Load Current
90
V_IN = 12V
80
1000
70
100
60
50
10
40
30
1
20
10
0.1
1
10
LOAD CURRENT (mA)
0.1
100
3470 TA02
3470fd
1