DC/DC Voltage Inverter Spans Wide Voltage Range

Output power of 1W is guaranteed by the ST755 single-chip dc-to-dc voltage regulator. Generating an adjustable negative voltage from a positive supply ranging from 2.7V to 11V, the device uses a mixed bipolar-CMOS technology to integrate a current-mode PWM controller and a power MOSFET on the same chip so only a few external passive components are required. The current-mode controller allows a typical efficiency of 68% to be combined with low noise and high stability, with a typical line regulation of 0.1%/V and a typical load regulation of 0.003%/mA over the entire 0-200 mA output current range. In addition, the device features very low quiescent current values of 1.2 mA and 10 µA in shutdown mode. Available in 8-pin DIP and SO packages, the device also features a microprocessor-compatible shutdown input and a soft-start facility that limits inrush current when power is applied.