A new curvature compensation technique for CMOS voltage reference using |V_(GS_| and ?V_(BE)

摘要

A new mixed curvature compensation technique for CMOS voltage reference is presented, which resorts to two sub-references with complementary temperature characteristics. The first sub-reference is the source–gate voltage |V_(GS)|_p of a PMOS transistor working in the saturated region. The second sub-reference is the weighted sum of gate–source voltages |V_(GS)|_n of NMOS transistors in the subthreshold region and the difference between two base–emitter voltages ?V_(BE) of bipolar junction transistors (BJTs). The voltage reference implemented utilizing the proposed curvature compensation technique exhibits a low temperature coefficient and occupies a small silicon area. The proposed technique was verified in 0.18μm standard CMOS process technology. The performance of the circuit has been measured. The measured results show a temperature coefficient as low as 12.7 ppm/℃ without trimming, over a temperature range from -40 to 120 ℃, and the current consumption is 50 μA at room temperature. The measured power-supply rejection ratio (PSRR) is -31:2 dB @ 100 kHz. The circuit occupies an area of 0.045 mm~2.