A low-cost high-accuracy CMOS smart temperature sensor

A high-accuracy CMOS temperature sensor with ADC and bus interface has been integrated in a 0.7µm CMOS process. Accuracy has been improved by applying a chopper technique and dynamic element matching. The circuit consumes 300µW@3.0V. Uncalibrated accuracy is typically better than 1°C for a temperature range of -20 to +100°C, measured on 112 samples from two different batches.