Patent ID: 7199742

Claim:
A digital-to-analog converter (DAC) comprising a plurality of current cells, and each of the current cells comprising: a level shifter connected to a first power terminal and a second power terminal for converting a first input signal and a second input signal into a first output signal and a second output signal, the level shifter comprising: a first module for converting the first input signal into the first output signal having a first NMOS transistor coupled to the first power terminal and a first PMOS transistor coupled to the second power terminal; and a second module for converting the second input signal into the second output signal having a second NMOS transistor coupled to the first power terminal and a second NMOS transistor coupled to the second power terminal; and a current source connected to the first power terminal and the second power terminal, the current source comprising: two cascaded MOS transistors connected to the first power terminal in series; a first MOS switch having a gate connected to the first module for receiving the first output signal; and a second MOS switch having a gate connected to the second module for receiving the second output signal; wherein the first power terminal supplies a digital high voltage level and the second power terminal supplies a digital low voltage level.