A bandgap reference is an electronic circuit that generates a stable voltage reference based on the semiconductor properties of materials. It utilizes the temperature-independent energy gap of semiconductors, ensuring that the output voltage remains consistent across varying temperatures and supply voltages. This stability is crucial for precision applications in electronics. Typically, a bandgap reference circuit combines bipolar junction transistors (BJTs) and resistors to create a voltage that is approximately 1.2 volts. This reference voltage is widely used in integrated circuits, such as analog-to-digital converters and voltage regulators, to improve accuracy and performance in electronic devices.