A digital television chip having a reduced layout size is disclosed, comprising a multiplexer, and first and second converting units. The multiplexer, according to a control signal, outputs one of S-video signals SY and SC to the first converting unit, outputs the other of the S-video signals SY and SC to the second converting unit, outputs one of Tuner CVBS signals VIF and SIF to the first converting unit, outputs the other of the Tuner CVBS signals VIF and SIF to the second converting unit, or outputs a CVBS Line-in Video signal to one of the first and second converting units, for reducing the size of the chip. The first converting unit converts one of the S-video signals SY and SC, one of the Tuner CVBS signals VIF and SIF, or the CVBS Line-in Video signal into a first digital signal for signal processing. The second converting unit converts one of the S-video signals SY and SC, one of the Tuner CVBS signals VIF and SIF, or the CVBS Line-in Video signal into a second digital signal for signal processing.