DESCRIPTION
The LT®1931/LT1931A are the industry’s highest power inverting SOT-23 current mode DC/DC converters. Both parts include a 1A integrated switch allowing high current outputs to be generated in a small footprint. The LT1931 switches at 1.2MHz while the LT1931A switches at 2.2MHz. These high speeds enable the use of tiny, low cost capacitors and inductors 2mm or less in height. The LT1931 is capable of generating –5V at 350mA or –12V at 150mA from a 5V supply, while the LT1931A can generate –5V at 300mA using significantly smaller inductors. Both parts are easy pin-for-pin upgrades for higher power LT1611 applications.

FEATURES
■ Fixed Frequency 1.2MHz/2.2MHz Operation
■ Very Low Noise: 1mVP-P Output Ripple
■ –5V at 350mA from 5V Input
■ –12V at 150mA from 5V Input
■ Uses Small Surface Mount Components
■ Wide Input Range: 2.6V to 16V
■ Low Shutdown Current: <1µA
■ Low VCESAT Switch: 400mV at 1A
■ Pin-for-Pin Compatible with the LT1611
■ Low Profile (1mm) ThinSOTTM Package

APPLICATIONS
■ Disk Drive MR Head Bias
■ Digital Camera CCD Bias
■ LCD Bias
■ GaAs FET Bias
■ Local Low Noise/Low Impedance Negative Supply