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

The LT1073 is a versatile micropower DC/DC converter. The device requires only three external components to deliver a fixed output of 5V or 12V. The very low minimum supply voltage of 1V allows the use of the LT1073 in applications where the primary power source is a single cell. An on-chip auxiliary gain block can function as a low-battery detector or linear post-regulator.

Average current drain of the LT1073-5 used as shown in the Typical Application circuit below is just 135µA unloaded, making it ideal for applications where long battery life is important. The circuit shown can deliver 5V at 40mA from an input as low as 1.25V and 5V at 10mA from a 1V input.

The device can easily be configured as a step-up or step-down converter, although for most step-down applications or input sources greater than 3V, the LT1173 is recommended. Switch current limiting is user-adjustable by adding a single external resistor. Unique reverse-battery protection circuitry limits reverse current to safe, nondestructive levels at reverse supply voltages up to 1.6V.

APPLICATIONS

* Pagers

* Cameras

* Single-Cell to 5V Converters

* Battery Backup Supplies

* Laptop and Palmtop Computers

* Cellular Telephones

* Portable Instruments

* 4mA to 20mA Loop Powered Instruments

* Hand-Held Inventory Computers

* Battery-Powered α, β and γ Particle Detectors

* No Design Required

* Operates at Supply Voltages From 1.0V to 30V

* Consumes Only 95µA Supply Current

* Works in Step-Up or Step-Down Mode

* Only Three External Off-the-Shelf Components Required