A CMOS standard-process sensor

A CMOS circuit which generates a nearly constant voltage, with low sensitivity to temperature and supply voltage but strongly dependent on process variations is described. Detection of changes in the technological process is based on threshold voltage characteristics of a MOS transistor (i.e., the absolute values are significantly affected by the process but not the temperature coefficient, which remains almost constant). The output voltage of the process sensor ranges from 560 mV (fast-fast corner) to 1042 mV (slow-slow corner). The circuit is designed in 65 nm CMOS standard process and operates in the temperature range [-30, +130]°C with supply voltage from 2.2 V to 2.8 V (2.5 V nominal).