A Current-Mode Temperature Sensor with a ±1.56 °C Raw Error and Duty-Cycle Output in 16nm FinFET

Abstract

This brief presents a versatile thermal sensor, which features explicit simplicity on both circuit and system level. High accuracy without the need for calibration is possible by using the NPN bipolar device, available from a triple-well process. Combining the current-mode principle with an active integrator, the architecture can provide the temperature information directly through the duty-cycle of a single output signal. Not only the generation of PTAT and CTAT signals, but also the processing and basic A/D conversion is performed in the same feedback loop. This results in a robust and compact solution, that is independent from external clock or other control signals. A prototype sensor occupies only 2475 µm 2 silicon area in 16nm FinFET and consumes 30 µA at 0.95 V supply voltage. Across the consumer range, it achieves an accuracy of ± 1.56 ˚C (3σ) without calibration and a typical conversion speed of 40kS/sec., which are among best-inclass figures.