A Low Power Thyristor-Based CMOS Programmable Delay Element

Abstract — A delay element insensitive to power supply and temperature variations become important as circuit speeds increase. A delay element, based on a CMOS thyristor, is proposed in this paper. This thyristor uses current rather than voltage to control the delay, exhibiting a low power supply noise sensitivity of 9.43 % and a temperature variation sensitivity of 314 PPM/°C. A technique to cancel the charge sharing effect during switching is incorporated into the delay element to further enhance power supply insensitivity. The delay element is combined with a bandgap reference voltage generator to produce a digitally controlled variable delay line. Simulation results show that the proposed delay element has a lower power supply and temperature sensitivity than a classical chain of inverters. The power consumed by the proposed delay element is lower than an inverter chain, and is much lower than a differential delay element. I