Patent ID: 8093834

Claim:
A ballast control integrated circuit for a ballast driving a high intensity discharge (HID) lamp, the control integrated circuit comprising: a first circuit for controlling a DC to DC converter receiving a first DC voltage as input and providing an increased DC voltage as output, the first circuit including a driver for providing a pulsed signal to drive a first switch coupled to a flyback transformer of the DC to DC converter; and a second circuit for controlling a DC to AC converter, the second circuit controlling a switching circuit receiving the increased DC voltage and driving the HID lamp with an AC voltage, the second circuit comprising a driver circuit for driving the switching circuit, the switching circuit comprising an H-bridge switching circuit coupled to drive said HID lamp; said first circuit also including a circuit for sensing said first DC voltage, and if said first DC voltage is below a threshold, for enabling said first circuit to produce said increased DC voltage and for delaying operation of said second circuit until an adequate supply voltage for said control integrated circuit is provided to operate said driver circuit of said second circuit to ensure that switches in said switching circuit are driven fully on by said driver circuit.