GENERAL DESCRIPTION

The TC1235/1236/1237 are CMOS dual inverting charge pump voltage converters with a low power shutdown mode in MSOP 10-Pin packages. Only four external capacitors are required for full circuit implementation. Switching frequencies are 12kHz for the TC1235, 35kHz for the TC1236 and 125kHz for the TC1237. When the shutdown pin is held at a logic low, the device goes into a very low power mode of operation, consuming less than 1µA of supply current. These devices provide both a negative voltage inver sion (available at the –VIN output), and a negative doubling voltage inversion (available at the –2 VIN output) with a low output impedance capable of providing output currents up to 5mA for the –VIN output and 1mA for the –2VIN output. The input voltage can range from +1.8V to +5.5V.

FEATURES

■ 10-Pin MSOP Package

■ Operates from 1.8V to 5.5V

■ Up to 5mA Output Current at –VIN Pin

■ Up to 1mA Output Current at –2VIN Pin

■ Power-Saving Shutdown Mode

■ –VIN and –2VIN Outputs Available

■ Low Active Supply Current

.......................................... 120µA (MAX) for TC1235

.......................................... 360µA (MAX) for TC1236

.......................................... 1.5mA (MAX) for TC1237

■ Fully Compatible with 1.8V Logic Systems

TYPICAL APPLICATIONS

■ LCD Panel Bias

■ Cellular Phones PA Bias

■ Pagers

■ PDAs, Portable Dataloggers

■ Battery Powered Devices