A sub 1V self clocked switched capacitor bandgap reference with a current consumption of 180nA

This paper presents a bandgap reference capable of operating at supply voltages below 1V. In contrast to the vast majority of bandgap circuits the multiplication of the proportional to absolute temperature voltage is done by a switched capacitor network. Thus a reduced chip area is achieved. As a clock is needed for the switching, a relaxation oscillator is deeply integrated into the circuit. Combined the circuits provide a continuous sub bandgap voltage reference output of 615mV and a clock signal with a frequency of roughly 53kHz. The overall current consumption is 180nA at room temperature. The circuit is developed in a 130nm CMOS technology and occupies an active area of 0.0132mm².