A low voltage CMOS constant current-voltage reference circuit

The proposed CMOS current-voltage reference circuit consists of a traditional bandgap circuit based on the use of PMOS transistors in weak inversion. Its current is stabilized by an on-chip resistor with positive temperature coefficient. The voltage reference is produced by compensating the positive temperature coefficient of a resistor by the negative temperature coefficient of the diode connected PMOS transistor by driving the constant current of the current reference through them. The simulated temperature coefficients of the voltage and the current were less than 85 ppm/°C and 54 ppm/°C, respectively, in the worst-case simulation over the temperature range of -10°C to 70°C without trimming, and the supply-voltage coefficients of the voltage and current were 0.16% over the supply voltage range of 1.1 V to 2.2 V.