A high-speed CMOS on-chip temperature sensor

A high-speed on-chip temperature sensor is implemented in a 0.6µm CMOS process for the purpose of quickly detecting circuit overheating. By using a high-speed differential current switch and a switched-current proportional-to-absolute-temperature PTAT (ΔVBE) generator, this temperature sensor is able to operate at high speed without suffering from switching noise or input offset problems. A sensing amplifier with chopped output stage and a low-offset current mirror minimize the offset at the output stage. Analog-to-Digital conversion is achieved by a low-power continuous-time switched-current ΣΔ modulator with a 10-bit resolution within 0°C to 150° at a 100kHz output rate. Powered by a single 3.3V power supply, this sensor has an active area of 0.11mm²and a power consumption of 2.9mW with a 40MHz clock.