LT1317 Datasheet | Linear Technology

LT1317/LT1317B Micropower, 600k Hz PWM DC/DC Converters Features s s s s s s DESCRIPTION The LT ®1317/LT1317B are micropower, fixed frequency step-up DC/DC converters that operate over a wide input voltage range of 1.5V to 12V. The LT1317 Features automatic shifting to power saving Burst Mode TM operation at light loads. High efficiency is maintained over a broad 300µA to 200m A load range. Peak switch current during Burst Mode operation is kept below 250m A for most operating conditions which results in low output ripple voltage, even at high input voltages. The LT1317B does not shift into Burst Mode operation at light loads, eliminating low frequency output ripple at the expense of light load efficiency. The LT1317/LT1317B contain an internal low-battery detector with a 200m V reference that stays alive when the device goes into shutdown. No-load quiescent current of the LT1317 is 100µA and shuts down to 30µA. The internal NPN power switch handles a 500m A current with a voltage drop of just 300m V. The LT1317/LT1317B are available in MS8 and SO-8 packages. , LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a trademark of Linear Technology Corporation. s s s 100µA Quiescent Current Operates with VIN as Low as 1.5V 600k Hz Fixed Frequency Operation Starts into Full Load Low-Battery Detector Active in Shutdown Automatic Burst Mode Operation at Light Load (LT1317) Continuous Switching at Light Loads (LT1317B) Low VCESAT Switch: 300m V at 500m A Pin for Pin patible with the LT1307/LT1307B U APPLICATIONS s s s s s s s s Cellular Telephones Cordless Telephones Pagers GPS Receivers Battery Backup Portable Electronic Equipment Glucose Meters Diagnostic Medical Instrumentation TYPICAL APPLICATION L1 10µH 2-Cell to 3.3V Converter Efficiency D1 90 2.2VIN 3VIN + C1 47µF VIN LBI LT1317 SHDN VC RC 33k CC 3.3n F SW FB LBO GND R1 1M 1% R2- 604k 1% 3.3V 200m A EFFICIENCY (%) 2 CELLS SHUTDOWN + C2 47µF 1317 F01 D1:...