Highly-linear wide-range voltage-controlled delay element with body bias technique

Abstract

A highly-linear wide-range voltage-controlled delay element in 55 nm CMOS technology at 1.2 V supply is presented. Unlike traditional voltage-controlled delay unit, the proposed delay unit utilizes two transistors as auxiliary current path and employs body bias technique to widen applicable range of control voltage. At the same time, it guarantees correct output logic voltage and high linearity. Moreover, a simple model is proposed to get a better understanding of circuit characteristics. The unit delay ranges from 110ps to 236 ps. When sweeping control voltage from 0 to 1.2 V at 200 MHz (TT corner 27 °C), calculated gain is 14.2ps/mv and delay quadrature error (DQE) is 6.6%. While operating at 200 MHz, the maximum simulated power consumption is 15.09μW.