A BJT-based temperature sensor with a packaging-robust inaccuracy of ±0.3°C (3s) from -55°C to +125°C after heater-assisted voltage calibration

Abstract

This paper presents a BJT-based temperature sensor, which can be accurately trimmed in both ceramic and plastic packages, on the basis of purely electrical measurements at room temperature. This is achieved by combining the voltage-calibration technique from [1] with an on-chip heater, which can heat the sensing BJTs from room temperature to ∼85°C in 0.5s. Measurements show that the sensor can then be trimmed to an inaccuracy of ±0.3°C (3σ) over the military range (-55 to +125°C). This is similar to the inaccuracy obtained after conventional temperature calibration, i.e., at well-defined temperatures, but requires much less calibration time and infrastructure.