Patent ID: 6108215
Filing Date: 2000-08-22
Classification: H02M,H05B,Y02B

Abstract:
A computer system comprising:a display assembly including a cold cathode fluorescent lamp; andan inverter circuit connected to the cold cathode fluorescent lamp, the inverter circuit including:a pulse width modulator coupled to receive a reference signal and a feedback signal indicative of current in the cold cathode fluorescent lamp, the pulse width modulator being operable to generate driving signals;a synchronously switching voltage regulator having a high side driver and a low side driver coupled to receive the driving signals from the pulse width modulator;a self-resonant converter coupled between the synchronously switching voltage regulator and the cold cathode fluorescent lamp, the self-resonant converter being coupled to receive a voltage signal from the synchronously switching voltage regulator, the self-resonant converter being operable to generate another voltage signal for illuminating the cold cathode fluorescent lamp; anda timer circuit coupled to transmit and receive signals from the self-resonant converter and to receive signals from a zero voltage detector, the timer circuit being operable to control frequency of oscillation in the self-resonant converter based on the signals from the self-resonant converter and the zero voltage detector.