Base resistance cancellation method and related methods, systems, and devices
Methods, systems and devices of the present disclosure involve techniques for cancelling base resistance error otherwise present in remote temperature sensors such as remote diode temperature sensors. In one or more embodiments, measurement logic configured to determine a temperature of or near a remote temperature sensor may be configured to determine an error cancelling coefficient and to calculate a temperature value, at least in part, responsive to the error cancelling coefficient. In some cases, error cancelling coefficients may be determined using one or more calibration techniques.
1. A sensing circuit for a remote diode temperature sensor, comprising:
a biasing circuit configured to provide a number of biasing currents to at least one sensing path of two sensing paths associated with a remote temperature sensor;
a sensing circuit configured to measure voltage levels exhibited by a voltage across the two sensing paths while the biasing currents are being provided to the at least one sensing path; and
a measurement circuit configured to:
determine at least two voltage changes responsive to the measured voltages; and
determine a temperature sensed by the remote temperature sensor responsive to the at least two voltage changes, the bias currents, and an error cancelling coefficient,
wherein the error cancelling coefficient comprises a value for a route resistance of the two sensing paths.
2. The sensing circuit of claim 1 , wherein the number of biasing currents comprises pairs of biasing currents.
3. The sensing circuit of claim 1 , wherein each biasing current of the number of biasing currents are proportional to each of the other biasing currents of the number of biasing currents.
4. The sensing circuit of claim 3 , wherein each biasing current of the number of biasing currents is different than each of the other biasing currents of the one or more biasing currents.
5. The sensing circuit of claim 1 , wherein each biasing current of the number of biasing currents is a multiple of a specified current.
6. The sensing circuit of claim 5 , wherein the multiple is of the range 1x to 20x, inclusive.
7. The sensing circuit of claim 1 , wherein the biasing circuit is configured to provide a first biasing current that is a first multiple of a specified current, and the sensing circuit is configured to measure a first voltage level of the voltage across the two sensing paths while the first biasing current is being provided.
8. The sensing circuit of claim 7 , wherein the biasing circuit is configured to provide a second biasing current that is a second multiple of the specified current, and the sensing circuit is configured to measure a second voltage level of a voltage across the two sensing paths while the second biasing current is being provided.
9. The sensing circuit of claim 1 , wherein the measurement logic circuit is configured to:
determine a route resistance associated with the at least one sensing path operatively coupled to the two sensing paths responsive to the determined changes in voltage level; and
determine a base resistance responsive to the determined changes in voltage level.
10. The sensing circuit of claim 9 , wherein the error cancelling coefficient is a sum of the route resistance and the base resistance.
11. A method of cancelling a base-resistance error from a temperature calculation based on a remote temperature sensor, comprising:
providing a number of bias currents to at least one sensing path of two sensing paths associated with the remote temperature sensor;
measuring voltage levels exhibited by a voltage across the two sensing paths while the number of bias currents are provided to the at least one sensing path;
determining at least two voltage level changes responsive to the measured voltage levels; and
determining a temperature sensed by the remote temperature sensor responsive to the at least two voltage level changes, the bias currents, and an error cancelling coefficient,
wherein the error cancelling coefficient comprises a value for a route resistance of the two sensing paths.
12. The method of claim 11 , further comprising:
measuring a first voltage level change across the two sensing paths responsive to a first pair of bias currents;
measuring a second voltage level change across the two sensing paths responsive to a second pair of bias currents;
measuring a third voltage level change across the two sensing paths responsive to a third pair of bias currents; and
determining the error cancelling coefficient responsive to the first voltage level change, the second voltage level change, and the third voltage level change.
13. The method of claim 11 , further comprising:
measuring a first voltage level change across the two sensing paths responsive to a first pair of bias currents;
measuring a second voltage level change across the two sensing paths responsive to a second pair of bias currents; and
determining the error cancelling coefficient responsive to the first voltage level change and the second voltage level change.
14. The method of claim 13 , wherein the first pair of bias currents are each a different multiple of a specified bias current, and the second pair of bias currents are each a different multiple of the specified bias current.