ONE PIN CALIBRATION ASSEMBLY AND METHOD FOR SENSORS

• US 20100235130A1
• Filed: 03/11/2009
• Published: 09/16/2010
• Est. Priority Date: 03/11/2009
• Status: Active Grant

• Current Assignee: Kavlico Corporation (Sensata Technologies Holding Plc)
• Original Assignee: Kavlico Corporation (Sensata Technologies Holding Plc)
• Inventors: Hunter, Robert, Cornwall, Michael, CORDAN, Ernest
• Granted Patent: US 8,224,611 B2
• Time in Patent Office: Days
• US Class Current: 702/104
• CPC Class Codes: G01D 18/008 with calibration coefficients stored in memory
• CPC Class Codes: G01K 15/00 Testing or calibrating of thermometers
• CPC Class Codes: G01K 15/005 Calibration
• CPC Class Codes: G01L 27/005 Apparatus for calibrating pressure sensors

Abstract

Described herein is a sensor assembly that can be calibrated after manufacture and a method for calibrating that assembly. The assembly comprises a sense element, microprocessor and a protection circuit. The assembly can use pins on the existing connector to input calibration data. The present invention also is a method of calibrating sensor outputs using an assembly that contains a protection circuit to prevent the sensor assembly from electrostatic discharge and high and reverse voltage.

Claims

1. An assembly for calibrating a sensor comprising:

a sensor element having at least one output signal;

a microprocessor capable of generating at least one output signal and receiving at least two input signals;

a protection circuit receiving at least two input signals and generating at least two output signals; and

a probe connected to the protection circuit for transmitting signals into the microprocessor through the protection circuit and to disable the protection circuit to allow calibration data signals to be input into the microprocessor from the protection circuit.

2. The assembly of claim 1 wherein the microprocessor contains compensation routines and calibration coefficient acceptance routines.

3. The assembly of claim 1 further comprising low-pass filters for filtering the compensated output signals from the microprocessor or other signal conditioning circuitry prior to their being input into the protection circuit.

4. The assembly of claim 1 wherein the sensor generates at least two output signals which are processed by the microprocessor.

5. The assembly of claim 4, wherein the protection circuit comprises at least two protection integrated circuits, one of each of the output sensor signals.

6. The assembly of claim 1 wherein after the microprocessor receives the calibration data, all signals input into the microprocessor from the sense element are compensated in accordance with the calibration data.

7. A calibration method for a sensor assembly having a sense element, a microprocessor, and a protection circuit, the method comprising the steps of,

attaching a probe to the sensor assembly which sends a signal to disable the protection circuit thereby allowing two way communication through the protection circuit;

enabling the microprocessor'"'"'s software calibration coefficient acceptance routine;

transmitting to the microprocessor the calibration data via the protection circuit; and

storing the calibration data in the non-volatile memory of the microprocessor such that the microprocessor calibrates the signals received from the sense element.

8. The method of claim 7, further comprising the step of bypassing any of the sensor assembly'"'"'s filters or signal conditioning circuitry.

9. The method of claim 7, further comprising the step of synchronizing the calibration data and the sense element output signals.

10. The method of claim 7, further comprising the step of, wherein once the microprocessor receives the calibration data, it does not accept additional calibration data.

11. The method of claim 7, further comprising the steps of using the calibration data to compensate for offset, gain, linearity, temperature variations and the like.

12. A method of calibrating a sensor assembly, the method comprising:

assembling a sensor assembly comprising at least a sensor, a microprocessor, a protection circuit and a connector;

calibrating the sensor assembly by using the connector for the output signals from the sensor assembly as the data input which calibrates the microprocessor; and

protecting the sensor assembly from over and reverse voltages and electrostatic discharge.