Patent ID: 8197123

Claim:
An automatically calibrating thermistor circuit comprising: a port coupleable to a thermistor exposed to a heated location over which a range of temperatures is expected, and configured to obtain a temperature reading representative of a temperature of said heated location; a first source, the first source providing a temperature reading associated with one end of said expected range of temperatures; and detection circuitry having an input selectively coupleable to the port and the first source and having an output, the detection circuitry including an amplifier coupled to the input and having a generally preset gain and a variable offset, the variable offset being set in response to an adjustable offset signal coupled thereto, and an A/D converter coupled to the amplifier and the output by which to provide a digital temperature signal correlated to a temperature reading at the input, the amplifier outputting amplified temperature reading signals across an expected operating range in relation to said expected temperature range of said heated location, the amplifier outputting a minimum value in response to the first source; and a processor coupled to the detection circuitry output, the processor selectively causing the first source to be coupled to the input of the detection circuitry in a calibration mode and the port to be coupled to the input of the detection circuitry in a normal operation mode, in the calibration mode the processor determining the adjustable offset signal based on the digital temperature signals obtained from the first source, the adjustable offset signal being operatively coupled to the variable offset of the amplifier such that the variable offset of the amplifier is set in response to the adjustable offset signal from the processor so that the variable offset of the amplifier is based on digital temperature signals obtained from the first source whereby to obtain the temperature reading representative of said temperature of said heated location in the normal operation mode.