High-robustness CMOS voltage reference for automotive applications with PVT variation tolerance

Abstract

This paper presents a robust CMOS voltage reference optimized for automotive applications, where reliability is crucial under varying environmental and operational conditions. The proposed design ensures high accuracy and stability across a wide range of process, voltage, and temperature (PVT) variations, which are typical in automotive environments. The proposed voltage reference uses two current generators exhibiting similar temperature characteristics to attain a low-temperature coefficient and low line sensitivity across a wide temperature range. By subtracting these two similar behavior currents to eliminate temperature-induced variations and applying the difference to a diode-connected NMOS transistor, the design ensures stability against temperature and supply variations. A trimming circuit is employed to calibrate the temperature sensitivity and reference voltage across various process corners to achieve consistent PVT stability under all conditions. The proposed voltage reference is designed and simulated using 180 nm CMOS technology. The simulation outcomes demonstrate that the reference voltage is 458.24 mV for a 1.2–5V supply voltage range with 0.027 %/V line sensitivity. The temperature coefficient is 19.83 ppm/°C for −40 °C–180 °C temperatures. The power supply rejection ratio is −72.36 dB at 1 KHz and −72.17 dB at 10 KHz. Furthermore, the output noise is 0.6μV/√Hz at 1 KHz and 0.18μV/√Hz at 10 KHz. The circuit consumes 8.7 μW of power and occupies a minimal area of 0.0011 mm².