Temperature Sensor with 292.3 nA/°C Sensitivity Using Double Current Subtraction
Tzung-Je Lee, Yin-Wen Lo · 2023
This paper proposes frequency-output temperature senor wide sensitivity. In traditional on-chip temperature sensor, the bandgap bias circuit is used to generate the PTAT (Proportional-to-Absolute Temperature) current, and converted to the output frequency. However, the sensitivity of the traditional PTAT current is only several tens of nA/°C, such that the input dynamic range is limited. This paper proposes the double current subtraction circuit to subtracting the CTAT current twice from the original PTAT current. The proposed design is carried out with a 0.18 um BCD HV process. The simulated sensitivity is 292.3 nA/°C, which is improved by 24.16 times. The detection error is from -0.62 °C to +0.69°C with the temperature range from -45 °C to 165 °C.