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 ModeTM operation at light loads. High efficiency is maintained over a broad 300µA to 200mA load range. Peak switch current during Burst Mode operation is kept below 250mA 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.

FEATURES
■ 100µA Quiescent Current
■ Operates with VIN as Low as 1.5V
■ 600kHz 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: 300mV at 500mA
■ Pin for Pin Compatible with the LT1307/LT1307B

APPLICATIONS
■ Cellular Telephones
■ Cordless Telephones
■ Pagers
■ GPS Receivers
■ Battery Backup
■ Portable Electronic Equipment
■ Glucose Meters
■ Diagnostic Medical Instrumentation