Description

This application report describes an alternative use of the TLC555-Q1 device as a charge pump. The square-wave output switching between the supply voltage and GND with few additional capacitors and diodes makes the device suitable for generating a positive or negative voltage multiplier. Using the TLC555-Q1 device as a charge pump is a cheap and easy solution for doubling, tripling, or inverting the supply voltage.

A charge pump can be used in automotive applications requiring reverse battery protection. A diode can also be used for battery protection; however, it causes a voltage drop and lowers efficiency. The charge pump is also capable of driving a MOSFET transistor with low drain-to-source on resistance.

Charge pumps can be used in a nonsynchronous rectifier when in low dropout mode to cause a high output ripple with light load. The charge-pump output can be connected to the BOOT pin for providing the necessary voltage to drive the upper-pass transistor.