Patent ID: 7522147

Claim:
A data switching circuit, comprising: a control unit, providing a switching signal, wherein the switching signal comprises a first status and a second status, and whenever a frame or a scan line of a TFT LCD starts, the switching signal alters the status; and a switching unit, having N input ends and N+1 output ends, wherein N is a positive integer number and the switching unit comprises: (N+1) inverters. receiving the switching signal respectively and outputting an inverted switching signal: and (2N+2) switch modules, wherein if i is a positive integer number and 1≦i≦N, an operation end of the first switch module is coupled to the switching signal, the first switch module turns off the connection between a first dummy data and the first output end of the switching unit as the switching signal takes the first status and turns on the connection between the first dummy data and the first output end of the switching unit as the switching signal takes the second status; an operation end of the 2i-th switch module is coupled to the inverted switching signal output from the i-th inverter, the 2i-th switch module turns off the connection between the i-th input end and the i-th output end of the switching unit as the inverted switching signal takes the first status and turns on the connection between the i-th input end and the i-th output end of the switching unit as the inverted switching signal takes the second status; an operation end of the (2i+1)-th switch module is coupled to the switching signal, the (2i+1)-th switch module turns off the connection between the i-th input end and the (i+1)-th output end of the switching unit as the switching signal takes the first status and turns on the connection between the i-th input end and the (i+1)-th output end of the switching unit as the switching signal takes the second status; an operation end of the (2N+2)-th switch module is coupled to the inverted switching signal output from the (N+1)-th inverter. the (2N+2)-th switch module turns off the connection between a second dummy data and the (N+1)-th output end of the switching unit as the inverted switching signal takes the first status and turns on the connection between the second dummy data and the (N+1)-th output end of the switching unit as the inverted switching signal takes the second status.