Reference voltage generator for temperature sensor with trimming capability at two temperatures

摘要

A temperature sensor circuit has a reference voltage generator that is trimmable at two temperatures for increased accuracy. The reference voltage generation section generates a reference voltage, the level of which is trimmable. A voltage divider section is connected to receive the reference voltage from the reference voltage generation section and generate a plurality of comparison voltage levels determined by the reference voltage and a trimmable resistance. An analog-to-digital converter can then be connected to a temperature dependent voltage section to receive the temperature dependent output voltage, such as a proportional to absolute temperature type (PTAT) behavior, and connected to the voltage divider section to receive the comparison voltage levels. The analog to digital converter generates an output indicative of the temperature based upon a comparison of the temperature dependent output voltage to the comparison voltage levels.

主权项

1. A temperature sensor circuit comprising:
a temperature dependent voltage section providing an output voltage having a linear type dependence on temperature; a reference voltage generation section generating a reference voltage, wherein the level of the reference voltage is trimmable at a first temperature value in a first trimming process; a voltage divider section connected to receive the reference voltage from the reference voltage generation section and generate therefrom a plurality of comparison voltage levels having a first level determined by the reference voltage and a second level dependent upon a first trimmable resistance, the second level being lower than the first, where the first trimmable resistance is trimmable at a second temperature value in a second trimming process that is separate from the first trimming process; and an analog to digital converter connected to the temperature dependent voltage section to receive the temperature dependent output voltage and connected to the voltage divider section to receive the comparison voltage levels, wherein the analog to digital converter generates an output indicative of the temperature based upon a comparison of the temperature dependent output voltage to the comparison voltage levels.