Datasheet LT3470A (Analog Devices)
| Manufacturer | Analog Devices |
| Description | Micropower Buck Regulator with Integrated Boost and Catch Diodes |
| Pages / Page | 20 / 1 — FEATURES. DESCRIPTION. Low Quiescent Current: 35µA at 12VIN to 3.3VOUT. … |
| Revision | C |
| File Format / Size | PDF / 747 Kb |
| Document Language | English |
FEATURES. DESCRIPTION. Low Quiescent Current: 35µA at 12VIN to 3.3VOUT. Integrated Boost and Catch Diodes
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LT3470A Micropower Buck Regulator with Integrated Boost and Catch Diodes
FEATURES DESCRIPTION
n
Low Quiescent Current: 35µA at 12VIN to 3.3VOUT
The LT®3470A is a micropower step-down DC/DC con- n
Integrated Boost and Catch Diodes
verter that integrates a 440mA power switch, catch diode n
Input Range: 4V to 40V
and boost diode into low profile 2mm × 3mm DFN n
3.3V at 250mA from 4V to 40V Input
package. The LT3470A combines Burst Mode and n
5V at 250mA from 5.7V to 40V Input
continuous operation to allow the use of tiny inductor n
Low Output Ripple: <10mV
and capacitors while providing a low ripple output to n <1µA in Shutdown Mode loads of up to 250mA. n Output Voltage: 1.25V to 16V n With its wide input range of 4V to 40V, the LT3470A can Hysteretic Mode Control n regulate a wide variety of power sources, from 2-cell Li-Ion Low Ripple Burst Mode® Operation at Light Loads n batteries to unregulated wall transformers and lead-acid Continuous Operation at Higher Loads n batteries. Quiescent current in regulation is just 35µA in Solution Size as Small as 50mm2 n a typical application while a zero current shutdown mode Low Profile (0.75mm) 2mm × 3mm Thermally disconnects the load from the input source, simplifying Enhanced 8-Lead DFN Package n power management in battery-powered systems. Fast cur- AEC-Q100 Qualified for Automotive Applications rent limiting and hysteretic control protects the LT3470A
APPLICATIONS
and external components against shorted outputs, even at 40V input. The LT3470A has higher output current and improved start-up and dropout performance compared n Automotive Battery Regulation n to the LT3470. Power for Portable Products All registered trademarks and trademarks are the property of their respective owners n Distributed Supply Regulation n Industrial Supplies n Wall Transformer Regulation
TYPICAL APPLICATION Efficiency and Power Loss vs Load Current
90 1000 V V IN IN = 12V 5.7V TO 40V 80 0.22µF VIN BOOST 70 100 POWER LOSS (mW) LT3470A 33µH VOUT OFF ON SHDN SW 5V 60 250mA BIAS 50 10 22pF 604k 1% 2.2µF FB 22µF EFFICIENCY (%) 40 GND 200k 1% 30 1 3470a TA01a 20 10 0.1 0.1 1 10 100 300 LOAD CURRENT (mA) 3470a TA01b Rev. C Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History related parts
FEATURES DESCRIPTION
n
Low Quiescent Current: 35µA at 12VIN to 3.3VOUT
The LT®3470A is a micropower step-down DC/DC con- n
Integrated Boost and Catch Diodes
verter that integrates a 440mA power switch, catch diode n
Input Range: 4V to 40V
and boost diode into low profile 2mm × 3mm DFN n
3.3V at 250mA from 4V to 40V Input
package. The LT3470A combines Burst Mode and n
5V at 250mA from 5.7V to 40V Input
continuous operation to allow the use of tiny inductor n
Low Output Ripple: <10mV
and capacitors while providing a low ripple output to n <1µA in Shutdown Mode loads of up to 250mA. n Output Voltage: 1.25V to 16V n With its wide input range of 4V to 40V, the LT3470A can Hysteretic Mode Control n regulate a wide variety of power sources, from 2-cell Li-Ion Low Ripple Burst Mode® Operation at Light Loads n batteries to unregulated wall transformers and lead-acid Continuous Operation at Higher Loads n batteries. Quiescent current in regulation is just 35µA in Solution Size as Small as 50mm2 n a typical application while a zero current shutdown mode Low Profile (0.75mm) 2mm × 3mm Thermally disconnects the load from the input source, simplifying Enhanced 8-Lead DFN Package n power management in battery-powered systems. Fast cur- AEC-Q100 Qualified for Automotive Applications rent limiting and hysteretic control protects the LT3470A
APPLICATIONS
and external components against shorted outputs, even at 40V input. The LT3470A has higher output current and improved start-up and dropout performance compared n Automotive Battery Regulation n to the LT3470. Power for Portable Products All registered trademarks and trademarks are the property of their respective owners n Distributed Supply Regulation n Industrial Supplies n Wall Transformer Regulation
TYPICAL APPLICATION Efficiency and Power Loss vs Load Current
90 1000 V V IN IN = 12V 5.7V TO 40V 80 0.22µF VIN BOOST 70 100 POWER LOSS (mW) LT3470A 33µH VOUT OFF ON SHDN SW 5V 60 250mA BIAS 50 10 22pF 604k 1% 2.2µF FB 22µF EFFICIENCY (%) 40 GND 200k 1% 30 1 3470a TA01a 20 10 0.1 0.1 1 10 100 300 LOAD CURRENT (mA) 3470a TA01b Rev. C Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History related parts
