An Opamp-Less PVT Compensation Structure for Ramp Generator Circuit

Abstract

Accurate ramp signal, with low power dissipation, is highly demanded, for applications like counter ADC. This paper presents a novel low power ramp generator circuit with a negative feedback loop for compensation of the variations in process, voltage, and temperature (PVT). While using an opamp for PVT compensation has been essential in the previous ramp generator structures, the proposed ramp generator is opamp-less. Derived equations of the proposed ramp generator circuit show that PVT compensation structure works effectively. In addition, the circuit design and simulations were done in TSMC 0.18[Formula: see text][Formula: see text]m CMOS technology. Corner analysis shows that integral non-linearity (INL) of the ramp signal is about 3.7[Formula: see text]mV, for a wide temperature range, while the power dissipation of the circuit is about 1.16[Formula: see text][Formula: see text]W.