Precision human body temperature measurement based on thermistor sensor

An analog front-end, with a new temperature calibration method, for an accurate temperature measurement of a human body has been presented. The discussed AFE consists of a current reference, a precision current source, a programmable gain amplifier, a voltage source proportional to absolute temperature and on-chip temperature calibration resistor. Human body temperature can be measured in the range from +25 °C to +45 °C at the operating temperature of an IC in the range from -40 °C to +125 °C with 0.1 °C precision. The presented analog front-end consumes no more than 180 uW and was designed in UMC CMOS 130 nm technology.