Semiconductor temp. sensor measurement circuit - permits sensor variation compensation, involves monitoring sensor self-capacitance and evaluates corresponding error

摘要

The measurement system contains a semiconductor temp. sensor (1) and a measurement circuit (2) for temp. measurement, and this automatically detects and corrects for variations in the functioning of the temp. sensor (1) during operation. This is achieved by use of a monitoring device (3) which is connected in parallel with the temp. measurement circuit (2). The monitoring device determines the self-capacitance of the semiconductor temp. sensor. An evaluation device is connected between the temp. measurement circuit and the monitoring device. The evaluation device detects the indication error arising from the capacitance variation and produces a corresp. correction signal for the display or a sensor failure signal as required. The strong variation in capacitance with moisture penetration is also taken into account.