Mixed-Signal Circuit Design Driven by Analysis: ADCs, Comparators, and PLLs

Speaker: Hao Xu
Affiliation: Ph.D. Candidate - UCLA

Abstract: Mixed-signal circuits often involve time-varying components and hard non-linearity that have not been systematically characterized, designers are thus forced to rely on intensive simulations. We will present study on fundamental circuit principles that answer these questions and enable optimized designs.

In the first part, we present the complete study on regenerative comparators. The regenerative comparator circuit which lies at the heart of A/D conversion, slicer circuits, and memory sensing, is unstable, time-varying, nonlinear, and with multiple equilibria. That does not mean, that it cannot be understood with simple equivalent circuits that reveal its dynamics completely, and enable it to be designed to specifications on static and dynamic offset and noise. The analysis is applied to the static latch, strongArm latch and other variants.

In the second part, we present a linearized analysis of bang-bang phase-locked loops (PLLs) in the frequency domain that is complete and self-consistent. It enables the manual design of frequency synthesis PLLs for loop bandwidth, output phase noise and minimum jitter. Tradeoffs between various parameters of the loop become clear.

In the third part, we present a 2.5GS/s 10bit interleaved ADC without active amplifier and inter-channel calibration. Design trade-offs are analytically explored and verified by measurement. This works shows the limit of interleaved ADC without sophisticated calibration scheme.

Biography: Hao Xu received the B.S. degree in mircoelectronics from Fudan University, Shanghai, China, in 2010. He received the M.S. degree in Electrical Engineering from the University of California, Los Angeles, in 2012, where he is currently working towards Ph.D. degree.

For more information, contact Prof. Asad A. Abidi ()

Date(s) - Nov 07, 2018
12:00 pm - 2:00 pm

E-IV Faraday Room #67-124
420 Westwood Plaza - 6th Flr., Los Angeles CA 90095