Patent ID: 7319347

Claim:
An energy recovery circuit comprising: a pull-up device, which is connected between a power supply voltage terminal and an output node and transmits a power supply voltage to the output node; a pull-down device, which is connected between a ground voltage terminal and the output node and transmits a ground voltage to the output node; an energy recovery capacitor, which is connected between the output node and the ground voltage terminal; a load capacitor, which is connected to the output node; and a bidirectional high voltage switching device, which is connected between the output node and the energy recovery capacitor, wherein the bidirectional high voltage switching device comprises an N-channel symmetric double diffused metal oxide semiconductor field effect transistor (DMOS FET) having a drain and a source formed symmetrically to each other and transferring voltages from the energy recovery capacitor to the load capacitor, and a P-channel symmetric DMOS FET having a drain and a source formed symmetrically to each other for and transferring voltages from the load capacitor to the energy capacitor, the N-channel and P-channel symmetric DMOS FETs are connected to each other in parallel.