| 20100052544 | PWM CONTROLLING CIRCUIT, APPARATUS OF CONTROLLING BACKLIGHT COMPRISING THE SAME, AND APPARATUS OF DRIVING BACKLIGHT COMPRISING THE APPARATUS OF CONTROLLING BACKLIGHT - A pulse width modulation (PWM) control circuit is disclosed. The PWM control circuit includes an adder summing up an input signal and a conversion signal to generate a summation signal, a quantizer quantizing the summation signal generated by the adder to output a quantization signal, a subtractor subtracting the summation signal from the quantization signal to output a subtraction signal, a filter filtering the subtraction signal to have a predetermined bandwidth to limit the frequency and converting the subtraction signal to provide the adder with the conversion signal, and a synchronization gate controlling the quantization signal by the gate signal inputted therein to output a PWM control signal having a same duty ratio as the quantization signal and a portion of which is off, and temporarily stopping an operation of the adder, the quantizer, the subtractor and the filter. | 03-04-2010 |
