A High PSRR CMOS Voltage and Current Reference in One Circuit Without Amplifier for Low Power Applications

This paper presents a low power voltage reference and current reference in one circuit. The reference voltage is the sum of the complementary to absolute temperature (CTAT) gate-source voltage of a MOSFET operating in the subthreshold region and a scaled version of the proportional to absolute temperature (PTAT) $\Delta \mathrm{V}_{\mathrm{G}\mathrm{S}}$ of two MOSFETs operating in subthreshold region. The generated temperature independent reference current is the ratio of the reference voltage and a resistance. The proposed circuit does not use an operational transconductance amplifier (OTA) to generate the reference current, thereby eliminates the variation in current due to any offset of the OTA. Furthermore, the circuit uses a native MOSFET for ameliorating the DC PSRR. The proposed circuit is designed in a 130nm CMOS process. The circuit works with a minimum supply voltage of 1. 2V while generating a reference voltage of around 0. 7V and a reference current of around 100nA. A TC of 100 ppm/°C for the reference voltage and a TC of 108 ppm/°C for the reference current are noted for mismatch and process variations from Monte-Carlo simulations for 300 samples. The circuit consumes only 240nW of power, which makes it suitable for ultra-low power applications.