LM2781 Overview
The LM2781 is a charge pump that inverts an input voltage in the range of 1.8V to 5.5V to the corresponding output voltage of -1.8V to -5.5V. With use of three or four low-cost external ceramic capacitors, the LM2781 can provide up to 50mA of output current. The LM2781 operates at a 210kHz typical switching frequency to minimize supply current (0.7mA typ.).