A highly linear and large bandwidth fully differential CMOS line driver suitable for high-speed data transmission applications
This article describes a large bandwidth and low distortion line driver in a 0.35-mum CMOS process. The line driver drives a 75 Q resistive load. Its power consumption is 140 mW from a 3.3 V supply. It has a relatively high -3 dB bandwidth (260 MHz) with good phase margin of about 70 degrees. It shows very low THD (-74.5 dB) when drives the load with a 3.3 V peak to peak sine wave at 10 MHz. This architecture reduces the distortion by locating the input differential pair inside the feedback loop and eliminating the distortion of the feedback transistors, which is dominant source of distortion at high frequencies. Thus, it improves the linearity of the output voltage in comparison with previous designs.
linearity line driver distortion thd folded cascode class a/b