| 主权项 |
1. ATV demodulator capable of calibrating output, comprising:
a TV digital-to-analog converter (TV DAC), which includes:
a master control switch having one end coupled to a predetermined voltage level, the master control switch being controlled by a calibration signal, wherein when the calibration signal turns ON the master control switch, a master current is generated;a current distribution circuit coupled to the master control switch, the current distribution circuit distributing the master current according to an image control signal, so as to generate an analog output signal at an output terminal of the TV demodulator;a first switch and a first resistor coupled to each other in series, wherein the first switch is coupled to the current distribution circuit and the output terminal; anda second switch and a second resistor coupled to each other in series, wherein the second switch is coupled to the current distribution circuit; and a calibration circuit coupled to the output terminal and the master control switch, wherein the calibration circuit generates the calibration signal for controlling the master control switch according to the analog output signal, so as to feedback control the master current. |
