System and method for precision compensation for the nonlinear offset and sensitivity variation of a sensor with temperature

• US 5,848,383 A
• Filed: 05/06/1997
• Issued: 12/08/1998
• Est. Priority Date: 05/06/1997
• Status: Expired due to Term

• Current Assignee: Sensata Technologies Incorporated (Sensata Technologies Holding Plc)
• Original Assignee: Integrated Sensor Solutions, Inc. (Texas Instruments, Inc.)
• Inventors: Yunus, Mohammad
• Primary Examiner(s): Arana, Louis M.
• Assistant Examiner(s): Bui, Bryan
• Application Number:
  US08/851,793
• Time in Patent Office: 581 Days
• Field of Search: 364/483, 364/557, 364/571.01, 364/571.02, 364/571.03, 364/571.04, 364/571.07, 73/700, 73/708, 73/763, 73/765, 73/766, 73/716-721, 73/1.88, 73/768, 327/512, 327/513, 702/99, 702/103-107, 341/118-120
• US Class Current: 702/104
• CPC Class Codes: G01D 3/022 having an ideal characteristic, map or correction data stored in a digital memory
• CPC Class Codes: G01D 3/0365 the undesired influence being measured using a separate sensor, which produces an influence related signal

Abstract

A method and system for calibrating a sensor is disclosed The method and system include receiving data relating to a plurality of temperature parameters and providing polynomial compensation of a temperature coefficient (TC). When providing polynomial compensation of the temperature coefficient, the method and system further include providing a first output and adding a second value to the first output. The first output is a distal temperature multiplied by a first value.

Claims

1. A digital compensation circuit for calibrating a sensor comprising:

an interface circuit for receiving data relating to a plurality of temperature parameters; and

means coupled to the interface circuit for providing polynomial compensation of a temperature coefficient (TC), the polynomial compensation means including;

means for providing a first output, the first output being a first value multiplied with a digitized temperature; and

means coupled to the first output providing means and the interface circuit for adding a second value using the first output.

2. The circuit of claim 1 in which the TC is a temperature coefficient of the sensitivity of a sensor.

3. The circuit of claim 1 in which the TC is a temperature coefficient of the offset of a sensor.

4. The circuit of claim 1 further comprising:

means coupled to the first output providing means and to the adder and multiply accumulator means for multiplexing a plurality of input signals to the first output providing means and to the adder means.

5. The circuit of claim 4 wherein the plurality of signals further comprise:

a plurality of temperature coefficient of the sensor offset calibration values; and

a plurality of temperature coefficient of the sensor sensitivity values.

6. The circuit of claim 5 wherein the plurality of signals further comprise:

a first temperature coefficient of the sensor offset calibration value plus a digitized temperature

multiplied by a second temperature coefficient of the sensor offset calibration value; and

a first temperature coefficient of the sensitivity of the sensor value plus a digitized temperature

multiplied by a second temperature coefficient of the sensitivity of the sensor value.

7. A digital compensation circuit for calibrating a sensor comprising:

an interface circuit for receiving data relating to a plurality of temperature parameters; and

first means coupled to the interface circuit for providing polynomial compensation of a first temperature coefficient (TC1), the first polynomial compensation means including means for providing a first outputs, the first output being a first value multiplied with a digitized temperature, and first adder or multiplier accumulator means coupled to the first output providing means and the interface circuit for adding a second value with the first output; and

second means coupled to the interface circuit for providing polynomial compensation of a high order temperature coefficient (TC_n), the second polynomial compensation means including means for providing a second output, the second output being a third value multiplied with the digitized temperature, and second adder or multiplier accumulator means coupled to the second output providing means and the interface circuit for adding a fourth value with the second output.

8. The circuit of claim 7 wherein the TC1 is a temperature coefficient of the sensitivity of the sensor;

and the TC_n is a temperature coefficient of the sensor offset.

9. The circuit of claim 8 in which the means for providing polynomial compensation further comprise:

means for providing a first output, the first output being a first value multiplied with a digitized temperature;

means coupled to the first output providing means for providing a second output, the second output being a second value added with the first output; and

second multiplying means coupled to the adder means and the interface circuit for multiplying the second output with the digital temperature.

10. The circuit of claim 9 wherein a digital temperature is represented by a digital data word or is indicated by a pulse density of a serial bit stream.

11. The circuit of claim 10 in which the TC is a temperature coefficient of the sensitivity of a sensor.

12. The circuit of claim 11 in which the TC is a temperature coefficient of the offset of a sensor.

13. A method for calibrating a sensor comprising the steps of;

(a) receiving data relating to a plurality of temperature parameters; and

(b) providing polynomial compensation of a temperature coefficient (TC), the step of providing polynomial compensation including the steps of;

(b1) providing a first output, the first output being a digital temperature multiplied by a first value; and

(b2) adding a second value to the first output.

14. The method of claim 13 in which the step of providing polynomial compensation further comprises:

(b1) providing a first output, the first output being a digital temperature multiplied by a first value;

(b2) providing a second output, the second output being a second value added to the first output; and

(b3) multiplying the second output by the digital temperature.

15. The method of claim 14 wherein the digital temperature is represented either by a digital word or is indicated by a pulse density of a serial bit stream.

16. A method for calibrating a sensor comprising the steps of:

a) receiving data relating to a plurality of temperature parameters;

b) providing polynomial compensation of a first temperature coefficient (TC1), the step of providing polynomial compensation of the first temperature coefficient including the steps of;

(b1) providing a first output, the first output being a digital temperature multiplied by a first value; and

(b2) adding a second value to the first output; and

c) providing polynomial compensation of a high order temperature coefficient (TC_n), the step of providing polynomial compensation of the high order temperature coefficient including the steps of;

(b1) providing a second output, the second output being a digital temperature multiplied by a third value; and

(b2) adding a fourth value to the second output.