LT1108-12

LT1108 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 110µA Supply Current Works in Step-Up or Step-Down Mode Only Four External Components Required Low Battery Detector Comparator On-Chip User Adjustable Current Limit Internal 1A Power Switch Fixed or Adjustable Output Voltage Versions Space Saving 8-Pin MiniDIP or S8 Package The LT1108 is a versatile micropower DC/DC converter. The device requires only four external components 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 LT1108 functions equally well in step-up, stepdown, or inverting applications. The LT1108 is pin-for-pin compatible with the LT1173, but has a duty cycle of 70%, resulting in increased output current in many applications. The LT1108 can deliver 150mA at 5V from a 2 AA cell input and 5V at 300mA from 9V in step-down mode. Quiescent current is just 110µA, making the LT1108 ideal for power conscious batteryoperated systems. 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 lockout circuit, or error amplifier. APPLICATI s s s s s s s s S Palmtop Computers 3V to 5V, 5V to 12V Converters 9V to 5V, 12V to 5V Converters LCD Bias Generators Peripherals and Add-On Cards Battery Backup Supplies Cellular Telephone...