Design of an ultra-low-power S/H bandgap voltage reference in a new BCD technology A bandgap is a voltage reference circuit that plays a major role within integrated circuits; it provides a reference that is invariant to supply voltage variations and temperature changes, so it is an essential building block for proper operation in a variety of applications, such as ADCs, DACs, DC-DC converters. The growing trend of ultra low power devices has led to the necessity for voltage and current references to consume less and less power, to affect as little as possible the consumption of final devices, but at the same time maintain the essential requirements of accuracy and invariance to temperature and power, which are commonly demanded.