| 摘要 |
A PWM signal selecting circuit of an inverter is provided to use commonly an external sync(pulse waveform signal) mode and an internal sync(direct current waveform signal) mode without changing an internal circuit. A PWM(Pulse-Width Modulation) signal selecting circuit of an inverter includes a detection unit(100), a filtering unit(300), a selecting unit(200), and a brightness control unit(400). The detection unit detects receives the brightness control signal of a pulse waveform type or a DC(Direct Current) waveform type and detects the waveform type of the inputted brightness control signal. If a brightness control signal outputted in the selecting unit is a pulse waveform, the brightness control unit outputs a brightness control signal synchronized to the brightness control signal. If the brightness control signal outputted in the selecting unit is a DC waveform, the brightness control unit outputs a brightness control signal synchronized to a driving frequency. |
