EMI resisting MOSFET-Only Voltage Reference based on the ZTC condition

Electromagnetic interference (EMI) can significantly degrade the performance of analog circuits, including DC voltage and current references, due to their limited Power Supply Rejection Ratio (PSRR). An EMI-resisting MOSFET-Only Voltage Reference is herein proposed, based on the MOSFET Zero Temperature Coefficient (ZTC) vicinity condition. The ZTC condition is analytically derived through a continuous MOSFET model that is valid from weak to strong inversion and a design methodology is proposed. The final circuit was designed in a 130 nm process and occupies around 0.0075 mm² of silicon area while consuming just 10.3 μW. Post-layout simulations presented a Voltage Temperature Coefficient (VTC) of 146 ppm/°C, for a temperature range from -55 to +125°C. An EMI source of 4 dBm (1 Vp_P amplitude) injected in the power supply of our circuit, according to the Direct Power Injection (DPI) specification results in a maximum DC Shift and Peak-to-Peak ripple of 22.7 % and 11m Vpp, respectively.