Zhao Gongyuan

A new curvature compensation technique for CMOS voltage reference using |VGS| and ΔVBE*

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 Δ 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 0.18 μ m 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 μ A 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 .