Distortion analysis of 30Gsample/s CMOS switched source follower
Liang H., Evans RJ., Skafidas E.
Volterra analysis of the ultra high-speed CMOS switched source follower (SSF) track and hold amplifier (THA) is presented based on a simplified RF model. Approximate expressions for the transfer function, the harmonic equations and third-order intermodulation distortion equation are derived respectively. Simulations based on a commercial available 65 nm CMOS process technology are performed with the SpectreRF circuit simulator. It is shown that when operating with ultra high input frequency , the total harmonic distortion (THD) linearity degrades progressively. Comparative SpectreRF simulated results for SSF THA have shown good agreement with Volterra analytical results by using the simplified BSIM4 RF model. ©2010 Crown.