A CMOS piecewise curvature-compensated voltage reference

This paper presents a novel approach to the design of a high-precision CMOS voltage reference. The proposed circuit utilizes MOS transistors instead of bipolar transistors to generate positive and negative temperature coefficient (TC) currents summed up to a resistive load to generate low TC reference voltage. A piecewise curvature-compensation technique is also used to reduce the TC of the reference voltage within a wider temperature range. The output reference voltage can be adjusted in a wide range according to different system requirements by setting different parameters such as resistors and transistor aspect ratios. The proposed circuit is designed for TSMC 0.6 μm standard CMOS process. Spectre-based simulations demonstrate that the TC of the reference voltage is 4.3 ppm/°C with compensation compared with 107 ppm/°C without compensation in the temperature ranges from −15 to 95 °C using a 1.5 V supply voltage.