Analog BIST Functionality for Microhotplate Temperature Sensors

In this letter, we describe a novel long-term microhotplate temperature-sensor calibration technique suitable for built-in self-test (BIST). The microhotplate thermal resistance (thermal efficiency) and the thermal voltage from an integrated platinum/rhodium thermocouple were calibrated against a polysilicon temperature-sensor calibration curve which drifts over time. Both of these temperature sensors, which cannot be directly calibrated, exhibit excellent long-term temperature stability and are appropriate for BIST functionality.