A 0.3μW, 7 ppm/°C CMOS Voltage reference circuit for on-chip process monitoring in analog circuits

A CMOS voltage reference circuit for on-chip process compensation in analog circuits has been developed in 0.35-mum CMOS process. The circuit generates a reference voltage based on threshold voltage of a MOSFET at absolute zero temperature. Theoretical analyses and experimental results showed that the circuit generates a quite stable reference voltage of 745 mV on average. The temperature coefficient and line sensitivity of the circuit were 7 pp/mdegC and 0.002%/V, respectively. The circuit consists of subthreshold MOSFETs with a low-power dissipation of 0.3 muW or less. By utilizing the nature of the reference voltage, which changes with the process conditions of threshold voltage in each LSI chip, the circuit can be used as an elementary circuit block for on-chip process compensation systems.