A bandgap reference is an electronic circuit that generates a stable voltage reference, independent of temperature and power supply variations. It utilizes the properties of semiconductor materials, specifically the energy gap between the valence and conduction bands, to produce a precise voltage output. This is crucial in various applications, such as analog-to-digital converters and voltage regulators. The output voltage of a bandgap reference is typically around 1.2 volts, which is close to the bandgap energy of silicon. By combining different semiconductor junctions, the circuit can achieve temperature compensation, ensuring consistent performance across a wide range of conditions. This reliability makes bandgap references essential in modern electronic devices.