A low-power, small-area and programmable bandgap reference

In this paper, we present a low-power, small-area and programmable bandgap reference, based on the reverse bandgap reference concept. It is implemented in a 65nm digital CMOS process with 1.2V power supply. It employs two switched capacitor amplifiers to weight temperature dependent voltages with opposite polarity. Programmability is achieved by adjusting a closed-loop gain of these two amplifiers. The implemented BGR generates three reference voltages, such as 0.591V (V_REF1), 0.872V (V_REF2) and 1.189V (V_REF3). In simulation, with ±10% supply voltage variation, the temperature coefficient (TC) of V_REF1, V_REF2 and V_REF3 is less than 43ppm/°C, 28ppm/°C and 33ppm/°C, respectivley, in the temperature range from -40°C to 100°C. The average power consumption is less than 40μW for V_REF1, 60μW for V_REF2 and 110μW for V_REF3. The layout area (excluding bonding pads) is 200μm by 190μm.