Date of Graduation


Document Type


Degree Name

Bachelor of Science in Electrical Engineering

Degree Level



Electrical Engineering


Mantooth, Alan


This thesis details the design process of a bandgap voltage reference (BGR) integrated circuit in a 180 nm CMOS process. A BGR provides a constant DC voltage across a range of operating temperatures and supply voltages. By its nature, the circuit is intended as a reference, not to provide current, so the output would be connected to a very high impedance, such as the gate of a transistor. At 27°C, this design provides a 955 mV reference voltage given a nominal VDD of 3 V. From 20°C to 175°C, the output voltage has a variance of 7.2 mV (approximately 0.8%) at the nominal supply voltage. Also, when the supply voltage changes from 2 V to 3.6 V, the output voltage changes by 10.9 mV (approximately 1.1%). CTAT (complimentary to absolute temperature) and PTAT (proportional to absolute temperature) devices placed in series provide stability over temperature variation, and a differential amplifier provides feedback, stabilizing the output over changes in VDD.


Bandgap voltage reference, circuits, output voltage, resistors, amplifier, negative feedback, supply voltage