Micropower DC/DC Converter Adjustable and Fixed 5V, 12V

The LT1107 is a versatile micropower DC/DC converter. The device requires only three 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 LT1107 functions equally well in step-up, step-down, or inverting applications.

The LT1107 is pin-for-pin compatible with the LT1111, but has a duty cycle of 70%, resulting in increased output current in many applications. The LT1107 can deliver 150mA at 5V from a 2AA cell input and 5V at 300mA from 24V in step-down mode. Quiescent current is just 320µA, making the LT1107 ideal for power-conscious battery operated systems. The 63kHz 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.

Applications

* Palmtop Computers

* 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

* Operates at Supply Voltages from 2V to 30V

* Consumes Only 320µA Supply Current

* Works in Step-Up or Step-Down Mode

* Only Three 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 SO-8 Package