A 2.87 ppm/°C 65 nm CMOS bandgap reference with nonlinearity compensation

Based on the review and analysis of two recently reported low temperature coefficient (TC) bandgap voltage references (BGRs), a new temperature compensation technique is presented. With the double-end piecewise nonlinearity correction method, the logarithm cancellation technique and the mixed-mode output topology, a BGR with high-temperature stability is realised based on 65 nm CMOS low-leakage process. The post-simulation results using Spectre show that this BGR produces an output voltage of about 953 mV with 2.5 V supply voltage, and the output voltage varies by only 0.16 mV from -40 degrees C to 125 degrees C. This low TC BGR has been used in a 65 nm CMOS touch screen controller, and the measurement shows that the output voltage of this BGR is about 949 mV varying by 0.44 mV from -40 degrees C to 125 degrees C. The TC of this BGR is about 2.87 ppm/degrees C, meeting the requirement of high-precision SoC application.