A High-Precision Bandgap Voltage Reference with Automatic Curvature-Compensation Technique

A high-precision bandgap voltage reference (BGR) with a novel curvature-compensation scheme is proposed in this paper. The temperature coefficient (TC) can be automatically optimized with a built-in adaptive curvature-compensation technique, which is realized in a digitization control way. An exponential curvature-compensation method is first adopted to reduce the TC in a certain degree, especially in low temperature range. Then, the temperature drift of BGR in higher temperature range can be further minimized by dynamic zero-temperature-coefficient point tracking (ZTCPT) with temperature changes. With the help of proposed adaptive signal processing, the output voltage of BGR can approximately maintain zero TC in a wider temperature range. Verification results of the BGR proposed in this paper, which is implemented in 0.35-mu m BiCMOS process, illustrate that the TC of 1.4 ppm/degrees C is realized under the power supply voltage of 3 V and the power supply rejection of the proposed circuit is -65 dB without any filter capacitor.