Temperature measurement system
View Patent ↗A temperature measurement system is disclosed. In accordance with some embodiments of the present disclosure, a temperature measurement system may comprise a resistor, a thermistor, a resistance-to-current converter configured to generate a current signal based on a resistance, an analog-to-digital converter (ADC) configured to receive a first current signal based on the resistor, convert the first current signal into a first digital signal, receive a second current signal based on the thermistor, and convert the second current signal into a second digital signal, and a calculation stage communicatively coupled to an ADC output and configured to determine a first digital value based on the first digital signal, determine a second digital value based on the second digital signal, calculate a resistance ratio based on the first digital value and the second digital value, and determine a temperature output value based on the resistance ratio.
1. A temperature measurement system, comprising:
a resistor;
a thermistor;
a buffer coupled to the resistor and the thermistor, the buffer configured to:
generate a first differential current signal based on the resistor;
generate a first complimentary differential current signal based on the resistor, wherein the first complimentary differential current signal has a polarity opposite to the first differential current signal;
generate a second differential current signal based on the thermistor; and
generate a second complimentary differential current signal based on the thermistor, wherein the second complimentary differential current signal has a polarity opposite to the second differential current signal; and
an analog-to-digital converter (ADC) coupled to the buffer and configured to:
convert the first differential current signal into a first digital signal;
convert the first complementary differential current signal into a first complementary digital signal;
convert the second differential current signal into a second digital signal; and
convert the second complementary differential current signal into a second complementary digital signal; and
a calculation stage communicatively coupled to an ADC output and configured to:
determine a first digital value based on the first digital signal and the first complimentary digital signal;
determine a second digital value based on the second digital signal and the second complimentary digital signal;
calculate a resistance ratio based on the first digital value and the second digital value; and
determine a temperature output value based on the resistance ratio.
2. The temperature measurement system of claim 1 , wherein the ADC comprises a sigma-delta ADC.
3. The temperature measurement system of claim 1 , wherein the ADC comprises a continuous-time integrator.
4. The temperature measurement system of claim 1 , wherein the resistance ratio comprises the first digital value divided by the sum of the first digital value and the second digital value.
5. The temperature measurement system of claim 1 , wherein the resistance ratio comprises the second digital value divided by the sum of the first digital value and the second digital value.
6. The temperature measurement system of claim 1 , further comprising a look-up map including a plurality of temperature output values and a corresponding plurality of resistance-ratio values.