charge pump的原理及应用

Charge Pump ConverterPrinciple of Charge Pump A charge pump is similar to a capacitive multiplier. A voltage multiplier makes an output voltage two, three or many times the peak to peak of input voltage. It has relative poor voltage regulation characteristics. For the highest performance, use low equivalent series resistance (ESR) capacitor (e.g., ceramic). Capacitive voltage conversion is obtained by switching a capacitor periodically. It first charges the capacitor by connecting it across a voltage source and then connects it to the output. During the on state, S1 and S3 are closed, which charges C1 to VIN level. During the off state, S2 and S4 are closed. The output voltage is VIN plus VC1, that is 2 VIN.

Fig.1

1

Ron is the resistance of the switch at conduction. ESR is the equivalent series resistance