Digital-to-analog converter (dac) circuit using tail current source shared sub-dacs

A digital-to-analog converter (DAC) circuit comprising:

• a first sub-DAC, comprising:
• a shared current source;
• a first signal path circuit, comprising:
• a first data switch circuit, controlled by a first set of control signals, wherein the first set of control signals depends on a first input data;
• and
• a first clock switch circuit, controlled by a first control signal, wherein the first control signal is independent of the first input data, and the first data switch circuit and the first clock switch circuit are series-connected between the shared current source and a data output port;
• a second signal path circuit, comprising:
• a second data switch circuit, controlled by a second set of control signals, wherein the second set of control signals depends on a second input data;
• and
• a second clock switch circuit, controlled by a second control signal, wherein the second control signal is independent of the second input data, and the second data switch circuit and the second clock switch circuit are series-connected between the shared current source and the data output port;
• and
• a return-to-zero (RZ) path circuit, controlled by at least one RZ control signal, wherein the at least one RZ control signal is independent of the first input data and the second input data, and the RZ path circuit is coupled between the shared current source and a dummy output node.