A CMOS voltage reference based on weighted ΔVGS for CMOS low-dropout linear regulators

A CMOS voltage reference, which is based on the weighted difference of the gate-source voltages of an NMOST and a PMOST operating in saturation region, is presented. The voltage reference is designed for CMOS low-dropout linear regulators and has been implemented in a standard 0.6-mum CMOS technology (V-thn approximate to \V-thp\ approximate to 0.9 V at 0 degreesC). The occupied chip area is 0.055 mm(2) The minimum supply voltage is 1.4 V, and the maximum supply current is 9.7 muA. A typical mean uncalibrated temperature coefficient of 36.9 ppm/degreesC is achieved, and the typical mean line regulation is +/-0.083%/V. The power-supply rejection ratio without any filtering capacitor at 100 Hz and 10 MHz are -47 and -20 dB, respectively. Moreover, the measured noise density with a 100-nF filtering capacitor at 100 Hz is 152 nV/rootHz and that at 100 kHz is 1.6 nV/rootHz.