LT1107 Micropower DC/DC Converter Adjustable and Fixed 5V, 12V UFEATURESDESCRIPTIO ■ Operates at Supply Voltages from 2V to 30V The LT®1107 is a versatile micropower DC/DC converter. ■ Consumes Only 320µA Supply Current The device requires only three external components to ■ Works in Step-Up or Step-Down Mode deliver a fixed output of 5V or 12V. Supply voltage ranges ■ Only Three External Components Required from 2V to 12V in step-up mode and to 30V in step-down ■ Low-Battery Detector Comparator On-Chip mode. The LT1107 functions equally well in step-up, step- ■ User Adjustable Current Limit down, or inverting applications. ■ Internal 1A Power Switch The LT1107 is pin-for-pin compatible with the LT1111, but ■ Fixed or Adjustable Output Voltage Versions has a duty cycle of 70%, resulting in increased output ■ Space Saving 8-Pin MiniDIP or SO-8 Package current in many applications. The LT1107 can deliver U 150mA at 5V from a 2AA cell input and 5V at 300mA from APPLICATIO S 24V in step-down mode. Quiescent current is just 320µA, making the LT1107 ideal for power-conscious battery- ■ Palmtop Computers operated systems. The 63kHz oscillator is optimized to ■ 3V to 5V, 5V to 12V Converters work with surface mount inductors and capacitors. ■ 24V to 5V, 12V to 5V Converters ■ LCD Bias Generators Switch current limit can be programmed with a single ■ Peripherals and Add-On Cards resistor. An auxiliary gain block can be configured as a ■ Battery Backup Supplies low-battery detector, linear post regulator, undervoltage ■ Cellular Telephones lock-out circuit, or error amplifier. ■ Portable Instruments , LTC and LT are registered trademarks of Linear Technology Corporation UTYPICAL APPLICATIOPalmtop Computer Logic SupplyEfficiency L1* 82 MBRS120T3 33µH 5V V 80 IN = 3V 150mA 47Ω 78 VIN = 2V 76 I V LIM VIN IN = 2.5V 74 2 × AA + SW1 + ALKALINE 47µF 100 LT1107-5 µF 72 CELLS SENSE EFFICIENCY (%) 70 GND SW2 68 66 64 * SUMIDA CD54-330K 1107 TA01 1 10 100 400 COILCRAFT DT3316-473 LOAD CURRENT (mA) 1107 TA02 1107fa 1