Datasheet LT3470A (Analog Devices)
| Fabricante | Analog Devices |
| Descripción | Micropower Buck Regulator with Integrated Boost and Catch Diodes |
| Páginas / Página | 20 / 1 — FEATURES. DESCRIPTION. Low Quiescent Current: 35μA at 12VIN to 3.3VOUT. … |
| Formato / tamaño de archivo | PDF / 207 Kb |
| Idioma del documento | Inglés |
FEATURES. DESCRIPTION. Low Quiescent Current: 35μA at 12VIN to 3.3VOUT. Integrated Boost and Catch Diodes
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LT3470A
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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 With its wide input range of 4V to 40V, the LT3470A can n Hysteretic Mode Control regulate a wide variety of power sources, from 2-cell Li-Ion – Low Ripple Burst Mode® Operation at Light Loads batteries to unregulated wall transformers and lead-acid – Continuous Operation at Higher Loads batteries. Quiescent current in regulation is just 35μA in n Solution Size as Small as 50mm2 a typical application while a zero current shutdown mode n Low Profile (0.75mm) 2mm × 3mm Thermally disconnects the load from the input source, simplifying Enhanced 8-Lead DFN Package power management in battery-powered systems. Fast cur- 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 n Automotive Battery Regulation improved start-up and dropout performance compared n Power for Portable Products to the LT3470. n Distributed Supply Regulation L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks n Industrial Supplies of Linear Technology Corporation. All other trademarks are the property of their respective n Wall Transformer Regulation owners.
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 604k 50 10 22pF 1% 2.2μF FB 22μF 40 EFFICIENCY (%) GND 200k 1% 30 1 3470a TA01a 20 10 0.1 0.1 1 10 100 300 LOAD CURRENT (mA) 3470a TA01b 3470afb 1
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 With its wide input range of 4V to 40V, the LT3470A can n Hysteretic Mode Control regulate a wide variety of power sources, from 2-cell Li-Ion – Low Ripple Burst Mode® Operation at Light Loads batteries to unregulated wall transformers and lead-acid – Continuous Operation at Higher Loads batteries. Quiescent current in regulation is just 35μA in n Solution Size as Small as 50mm2 a typical application while a zero current shutdown mode n Low Profile (0.75mm) 2mm × 3mm Thermally disconnects the load from the input source, simplifying Enhanced 8-Lead DFN Package power management in battery-powered systems. Fast cur- 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 n Automotive Battery Regulation improved start-up and dropout performance compared n Power for Portable Products to the LT3470. n Distributed Supply Regulation L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks n Industrial Supplies of Linear Technology Corporation. All other trademarks are the property of their respective n Wall Transformer Regulation owners.
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 604k 50 10 22pF 1% 2.2μF FB 22μF 40 EFFICIENCY (%) GND 200k 1% 30 1 3470a TA01a 20 10 0.1 0.1 1 10 100 300 LOAD CURRENT (mA) 3470a TA01b 3470afb 1