Patent ID: 7973494

Claim:
An electronic ballast for operating a lamp, comprising: a rectifier configured to receive input AC electrical power and having a rectifier output providing a rectified DC voltage; a DC-DC converter operative to convert the rectified DC voltage into a converter DC output voltage, the DC-DC converter comprising: a buck converter comprising: first and second buck converter capacitances coupled in series in a first circuit branch across the rectifier output, first and second buck converter diodes coupled in series in a second circuit branch across a buck converter output, and first and second buck converter switching devices operatively coupled between the rectifier output and the buck converter output and operative according to at least one buck converter control signal to selectively convert the rectified DC voltage to provide an intermediate DC voltage at the buck converter output, and a boost converter comprising: an inductance coupled with the buck converter output, a boost converter diode coupled between the inductance and a converter output, a boost converter capacitance coupled across the converter output, and a boost converter switching device coupled between the buck converter output and the converter output, and operable according to a boost converter control signal to selectively convert the intermediate DC voltage to provide the converter DC output voltage at the converter output; and an inverter operatively coupled to the converter output and operative to convert the converter DC output voltage to provide an AC output voltage at an inverter output to drive a lamp.