Patent ID: 7911150

Claim:
A discharge lamp lighting circuit comprising: a cold cathode fluorescent lamp; and a DC to AC inverter circuit for supplying AC power to drive said lamp, the DC to AC inverter circuit comprising: a tank circuit; a step up transformer having a primary winding and a secondary winding; a plurality of switches for converting a DC signal to an AC signal, the step up transformer stepping up the voltage of the AC signal and providing it to the lamp, the tank circuit filtering the AC signal provided to the lamp; a feedback signal line receiving a feedback signal indicative of an electrical condition of the lamp; an inverter controller integrated circuit having a plurality of inputs, comprising: a feedback input, the feedback signal line being electrically coupled to the feedback input, the inverter controller integrated circuit including feedback control circuitry that adjusts power delivered to the lamp, by opening and closing the switches based on the received feedback signal, and shuts down power to the lamp if the received feedback signal crosses a predetermined feedback threshold; a supply voltage input, the supply voltage input receiving a supply signal indicative of a supply voltage, the inverter controller integrated circuit including undervoltage lockout circuitry that shuts down power to the lamp if the received supply signal crosses a predetermined threshold indicating an undervoltage condition; and a multifunctional input, the inverter controller integrated circuit being configured to receive first and second input signals via the multifunctional input, the first input signal being used to implement a first function of the inverter controller integrated circuit during operation thereof, and the second input signal being used to implement a second function of the inverter controller integrated circuit during operation thereof.