AN APPLICATION OF DTMOS BASED OPAMP

Abstract

A bandgap voltage reference is a temperature independent voltage reference circuit widely used in integrated circuits. BGR is a basic design block of any analog circuit. The BGR generator circuit is designed to achieve the insensitive behaviour with respect to process, voltage and temperature (PVT) corners. The BGR supplies the reference voltage and the reference current to the analog design blocks such as a charge pump and a memory circuit. It commonly has an output voltage around 1.25V, close to the theoretical 1.22 eV bandgap of silicon at 0 K. This circuit concept was first published by David Hilbiber in 1964. An important part in the design of analog integrated circuits is to create reference voltages and currents with well defined values. To accomplish this on chip, so called bandgap reference circuits are commonly used. A typical application for this reference voltage is in analog to digital conversion, where the input voltage is compared to several reference levels in order to determine the corresponding digital value.