LT1107 Datasheet | Linear Technology

LT1107 Micropower DC/DC Converter Adjustable and Fixed 5V, 12V Features s s s s s s s s s DESCRIPTIO Operates at Supply Voltages from 2V to 30V Consumes Only 320µA Supply Current Works in Step-Up or Step-Down Mode Only Three External ponents Required Low-Battery Detector parator On-Chip User Adjustable Current Limit Internal 1A Power Switch Fixed or Adjustable Output Voltage Versions Space Saving 8-Pin Mini DIP or SO-8 Package The LT1107 is a versatile micropower DC/DC converter. The device requires only three external ponents to deliver a fixed output of 5V or 12V. Supply voltage ranges from 2V to 12V in step-up mode and to 30V in step-down mode. The LT1107 functions equally well in step-up, stepdown, or inverting applications. The LT1107 is pin-for-pin patible with the LT1111, but has a duty cycle of 70%, resulting in increased output current in many applications. The LT1107 can deliver 150m A at 5V from a 2AA cell input and 5V at 300m A from 24V in step-down mode. Quiescent current is just 320µA, making the LT1107 ideal for power-conscious batteryoperated systems. The 63k Hz oscillator is optimized to work with surface mount inductors and capacitors. Switch current limit can be programmed with a single resistor. An auxiliary gain block can be configured as a low-battery detector, linear post regulator, undervoltage lock-out circuit, or error amplifier. APPLICATI s s s s s s s s Palmtop puters 3V to 5V, 5V to 12V Converters 24V to 5V, 12V to 5V Converters LCD Bias Generators Peripherals and Add-On Cards Battery Backup Supplies Cellular Telephones Portable Instruments TYPICAL APPLICATI Palmtop puter Logic Supply L1- 33µH 47Ω ILIM 2 × AA ALKALINE CELLS VIN SW1 47µF LT1107-5 SENSE GND SW2 EFFICIENCY (%) MBRS120T3 5V 150m A 82 80 78 76 74 72 70 68 66 VIN = 2V VIN = 2.5V VIN = 3V + + 100µF - SUMIDA CD54-330K COILCRAFT DT3316-473 1107 TA01 Efficiency 1 10 100 LOAD CURRENT (m A) 400 1107 TA02 LT1107 ABSOLUTE AXI U RATI...