Patent ID: 7339558

Claim:
A driver circuit comprising: a first switch having a first end coupled to a first voltage source; a second switch having a first end coupled to an X side of an equivalent capacitor and a second end coupled to ground; a third switch having a first end coupled to a Y side of the equivalent capacitor and a second end coupled to ground; and an energy recovery circuit comprising: a first unit, having a first end coupled to the X side of an equivalent capacitor and a second end coupled to a second end of the first switch, for passing current of charging and/or discharging the equivalent capacitor from the X side; a second unit, having a first end coupled to the Y side of the equivalent capacitor and a second end coupled to the second end of the first switch, for passing current of charging and/or discharging the equivalent capacitor from the Y side; and a third unit coupled to the second end of the first switch and ground, the third unit comprising: a capacitor for charging and/or discharging the equivalent capacitor from the X side and/or the Y side; and a fourth switch coupled to the capacitor in series.