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

The LT1111 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 LT1111 functions equally well in step-up, step-down, or inverting applications.

The LT1111 oscillator is set at 72kHz, optimizing the device to work with off-the-shelf surface mount inductors. The device can deliver 5V at 100mA from a 3V input in step-up mode or 5V at 200mA from a 12V input in step-down mode.

Switch current limit can be programmed with a single resistor. An auxiliary open-collector gain block can be configured as a low-battery detector, linear post regulator, undervoltage lock-out circuit, or error amplifier.

For input sources of less than 2V use the LT1110.

Applications

* 3V to 5V, 5V to 12V Converters

* 9V to 5V, 12V to 5V Converters

* Remote Controls

* Peripherals and Add-On Cards

* Battery Backup Supplies

* Uninterruptible Supplies

* Laptop and Palmtop Computers

* Cellular Telephones

* Portable Instruments

* Flash Memory VPP Generators

* Operates at Supply Voltages from 2V to 30V

* Works with Surface Mount Inductors

* 72kHz Oscillator

* Only Three External Components Required

* Step-Up or Step-Down Mode

* 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