Patent ID: 8334721

Claim:
An integrated circuit (IC) comprising: a digital-to-analog converter configured to output a first differential signal; and an amplifier configured to process the first differential signal, and to output second differential signal, including a positive input section having a first internal transistor configured to receive a first input signal of the first differential signal; a negative input section having a second internal transistor configured to receive a second input signal of the first differential signal; and a plurality of current mirror output transistors configured to output the second differential signal, a first number of the current mirror output transistors being coupled to the first internal transistor to form a first current mirror to produce a first output signal of the second differential signal, and a second number of current mirror output transistors being coupled to the second internal transistor to produce the second output signal of the second differential signal; and a digital control unit configured to output first control signals to select the first number of the current mirror output transistors that contribute to the first output signal, and to output second control signals to select the second number of current mirror output transistors that contribute to the second output signal.