Switched Capacitor Voltage Converter

The LM828 CMOS charge-pump voltage converter inverts a positive voltage in the range of +1.8V to +5.5V to the corresponding negative voltage of −1.8V to −5.5V. The LM828 uses two low cost capacitors to provide up to 25 mA of output current.

The LM828 operates at 12 kHz switching frequency to reduce output resistance and voltage ripple. With an operating current of only 40 µA (operating efficiency greater than 96% with most loads), the LM828 provides ideal performance for battery powered systems. The device is in a tiny SOT-23 package.