POWER LOSS (mW)
LT3470
Micropower Buck Regulator
with Integrated Boost and
Catch Diodes
FEATURES DESCRIPTION
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Low Quiescent Current: 26A at 12V to 3.3V The LT 3470 is a micropower step-down DC/DC con-
IN OUT
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Integrated Boost and Catch Diodes verter that integrates a 300mA power switch, catch diode
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Input Range: 4V to 40V and boost diode into low profile 3mm 2mm DD and
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Low Output Ripple: <10mV ThinSOT packages. The LT3470 combines Burst Mode
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<1A in Shutdown Mode and continuous operation to allow the use of tiny induc-
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Output Voltage: 1.25V to 16V tor and capacitors while providing a low ripple output to
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200mA Output Current loads of up to 200mA.
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Hysteretic Mode Control
With its wide input range of 4V to 40V, the LT3470 can
Low Ripple Burst Mode Operation at Light Loads
regulate a wide variety of power sources, from 2-cell Li-Ion
Continuous Operation at Higher Loads
batteries to unregulated wall transformers and lead-acid
2
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Solution Size as Small as 50mm
batteries. Quiescent current in regulation is just 26A in
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Low Profile (0.75mm) 3mm 2mm Thermally
a typical application while a zero current shutdown mode
Enhanced 8-Lead DD and 1mm ThinSOT Packages
disconnects the load from the input source, simplifying
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AEC-Q100 Qualified for Automotive Applications
power management in battery-powered systems. Fast
current limiting and hysteretic control protects the LT3470
and external components against shorted outputs, even
APPLICATIONS
at 40V input.
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Automotive Battery Regulation
All registered trademarks and trademarks are the property of their respective owners.
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Power for Portable Products
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Distributed Supply Regulation
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Industrial Supplies
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Wall Transformer Regulation
TYPICAL APPLICATION
Efficiency and Power Loss vs Load Current
90 1000
V
IN V = 12V
IN
7V TO 40V
0.22F 80
V BOOST
IN
70 100
LT3470
33H
V
OUT
OFF ON SHDN SW 5V
60
200mA
BIAS
604k
50 10
22pF
1%
FB
2.2F 22F
40
GND
200k
1%
30 1
3470 TA01a
20
10 0.1
0.1 1 10 100
LOAD CURRENT (mA)
3470 TA02
Rev. E
1
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EFFICIENCY (%)LT3470
ABSOLUTE MAXIMUM RATINGS (Note 1)
V , SHDN Voltage ................................................... 40V Operating Temperature Range (Note 2)
IN
BOOST Pin Voltage .................................................. 47V LT3470E ...............................................40C to 85C
BOOST Pin Above SW Pin ........................................ 25V LT3470I ............................................. 40C to 125C
FB Voltage .................................................................. 5V LT3470H ............................................ 40C to 150C
BIAS Voltage .............................................................25V Storage Temperature Range .................. 65C to 150C
SW Voltage ................................................................V Lead Temperature (Soldering, 10 sec) ..................300C
IN
Maximum Junction Temperature
LT3470E, LT3470I ............................................. 125C
LT3470H ........................................................... 150C
PIN CONFIGURATION
TOP VIEW
TOP VIEW
FB 1 8 SHDN
SHDN 1 8 FB
BIAS 2 7 NC
NC 2 7 BIAS
9
BOOST 3 6 V
IN
V 3 6 BOOST
IN
SW GND
4 5 GND 4 5 SW
TS8 PACKAGE
8-LEAD PLASTIC TSOT-23
DDB8 PACKAGE
8-LEAD (3mm 2mm) PLASTIC DFN = 140C/W
JA
= 180C/W
JA
EXPOSED PAD (PIN 9) IS GROUND (MUST BE SOLDERED TO PCB)
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3470EDDB#TRMPBF LT3470EDDB#TRPBF LBPN 8-Lead (3mm 2mm) Plastic DFN 40C to 85C
LT3470IDDB#TRMPBF LT3470IDDB#TRPBF LBPP 40C to 125C
8-Lead (3mm 2mm) Plastic DFN
LT3470HDDB#TRMPBF LT3470HDDB#TRPBF LCNR 8-Lead (3mm 2mm) Plastic DFN 40C to 150C
LT3470ETS8#PBF LT3470ETS8#TRPBF LTBDM 8-Lead Plastic TSOT-23 40C to 85C
LT3470ITS8#PBF LT3470ITS8#TRPBF LTBPW 8-Lead Plastic TSOT-23 40C to 125C
LT3470HTS8#PBF LT3470HTS8#TRPBF LTCNQ 8-Lead Plastic TSOT-23 40C to 150C
LEAD BASED FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3470EDDB LT3470EDDB#TR LBPN 8-Lead (3mm 2mm) Plastic DFN
40C to 85C
LT3470IDDB LT3470IDDB#TR LBPP 8-Lead (3mm 2mm) Plastic DFN
40C to 125C
LT3470HDDB LT3470HDDB#TR LCNR
8-Lead (3mm 2mm) Plastic DFN 40C to 150C
LT3470ETS8 LT3470ETS8#TR LTBDM 8-Lead Plastic TSOT-23
40C to 85C
LT3470ITS8 LT3470ITS8#TR LTBPW 8-Lead Plastic TSOT-23
40C to 125C
LT3470HTS8 LT3470HTS8#TR LTCNQ 8-Lead Plastic TSOT-23
40C to 150C
Rev. E
2
For more information www.analog.com