Characterization of bandgap reference circuits designed for high energy physics applications

The objective of this work is to design a high performance bandgap voltage reference circuit in a standard commercial 65nm CMOS technology capable of operating in harsh radiation environments. A prototype circuit based on three different devices (diode, bipolar transistor and MOSFET) was fabricated and tested. Measurement results show a temperature variation as low as ±3.4mV over a temperature range of 170 ° C (-30°C to 140°C) and a line regulation at room temperature of 5.2%/V. Measured V REF is 690mV±15mV (3σ) for 26 samples on the same wafer. Circuits correctly operate with supply voltages in the range from 1.32V down to 0.78V. A reference voltage shift of only 7.6mV (around 1.1%) was measured after irradiation with 10keV X-rays up to an integrated dose of 225Mrad (SiO2).