Date of Award
Master of Engineering Science
Electrical and Computer Engineering
Dr. Robert Sobot
Bandgap reference plays a substantial role in integrated circuit. Traditionally, it provides a constant reference voltage of 1.2051/ for other blocks in the circuit while itself is independent of temperature and power supply. However, the development of CMOS technology has brought us into a new era of high integration and ultra-low power consumption. As the gate length scales down, it is crucial to build circuits that are able to work under a very low voltage power supply, for instance, lower than the bandgap voltage of 1.205V. Building bandgap circuits to generate the conven tional bandgap voltage under a low voltage power supply such as 1.2V or IV is no longer practical nor useful. Thus, bandgap references working under low-voltage and consuming low-power is becoming the trend of research and development nowadays.
In this thesis work, the potential structure of a low-voltage low-power bandgap reference is proposed, which is based on extracting a current that is a fraction of the traditional bandgap voltage. All the necessary blocks are designed to achieve the high accuracy bandgap reference, including bandgap core circuit, op-amp, start-up circuit and output stage. As a result, the designed bandgap reference is able to work under 1.2V power supply and provides an output reference voltage of 584.7mV. It has a variation of only 244.38fiV for the temperature range of 0°C ~ 125°C and has a variation of only 1.1mV for a power supply range of 1.08V ~ 1.32V. The layout design for the bandgap reference structure is also done carefully at the late stage, with an area of 100fj,m x 85¡xm.
Sun, Na, "A Low-Power Low-Voltage Bandgap Reference in CMOS" (2009). Digitized Theses. 3769.