Sensor including dual range ASIC

• US 20090049887A1
• Filed: 08/22/2007
• Published: 02/26/2009
• Est. Priority Date: 08/22/2007
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Wade, Richard A.
• Granted Patent: US 7,759,945 B2
• Time in Patent Office: Days
• US Class Current: 73/1.880
• CPC Class Codes: G01D 3/022 having an ideal characteristic, map or correction data stored in a digital memory
• CPC Class Codes: G01D 3/024 for range change; Arrangements for substituting one sensing member by another

Abstract

A sensor incorporates a dual range ASIC (Application Specific Integrated Circuit) for accurately sensing and measuring sensor input over extensive range along with an improved resolution. The sensor can incorporate an ASIC utilizing signals from a MEMS-based piezoresistive Wheatstone bridge. Signals can also come from capacitive pressure measurement sources. The signals can be converted to digital bit counts where calibration coefficients can be implemented to achieve high precision. The calibration coefficients corresponding to bit counts can be compared with transition points that are recorded into ASIC for effectively distinguishing different sensor ranges. The transition points can be stored in an EEPROM fabricated to suit ASIC applications.

Claims

1. A method for measuring at least one of pressure, temperature, speed, direction, light, over extensive range utilizing a dual range ASIC (Application Specific Integrated Chip), comprising:

applying a plurality of inputs corresponding to at least one sensor'"'"'s range to a sensing element;

converting a plurality of electrical signals obtained from said sensing element to a plurality of digital bit counts; and

calibrating said plurality of digital bit counts to generate a plurality of calibration coefficient.

2. The method of claim 1 further comprising:

determining if said plurality of calibration coefficient corresponding to a transition point wherein said transition point being stored in an ASIC; and

setting at least one resolution and at least one gain factor corresponding to said transition point and generating an output for said at least one sensing range.

3. The method of claim 1, wherein said is further comprised of a piezoresistive Wheatstone bridge fabricated as a micro electro mechanical systems.

4. The method of claim 1 wherein said plurality of digital bit counts can be generated utilizing an analog to digital interface.

5. The method of claim 1, wherein said transition points can be stored into an EEPROM fabricated to suit said ASIC for providing said at least one resolution.

6. The method of claim 1, wherein said input resolution effectively changes said gain factor thereby producing an output signal with a different slope.

7. The method of claim 1, wherein said transition point can be switched to another calibration coefficient and/or another input resolution based on said plurality of calibration coefficient.

8. A system for measuring pressure over extensive pressure range, comprising:

a pressure sensing element; and

a dual range Application Specific Integrated Chip (ASIC) programmed to apply a plurality of pressure points along a pressure range to said pressure sensing element, convert electrical signals obtained from said pressure sensing element to a plurality of digital bit counts, and calibrate said plurality of digital bit counts to generate a plurality of calibration coefficients.

9. The system of claim 8 further comprising said ASIC programmed to determine if said plurality of calibration coefficient correspond to a transition point stored in an ASIC and

10. The system of claim 9 further comprising said ASIC programmed to set at least one resolution and at least one gain factor corresponding to said transition point and generating an output for said at least one pressure range.

11. The system of claim 8, wherein said pressure sensing element is comprised of a piezoresistive Wheatstone bridge.

12. The system of claim 8 comprising said ASIC programmed to generate said plurality of digital bit counts utilizing an analog to digital interface.

13. The system of claim 8, further comprising an EEPROM adapted to store transition points and cooperate with said ASIC to provide said at least one resolution.

14. The method of claim 8, further comprising said ASIC programmed wherein said input resolution effectively changes said gain factor thereby producing an output signal with a different slope.

15. The method of claim 8, further comprising said ASIC programmed wherein said transition point can be switched to another calibration coefficient and/or another input resolution based on said plurality of calibration coefficients.

16. A system for measuring sensor input over extensive sensor input range utilizing a dual range ASIC (Application Specific Integrated Chip), comprising:

a data processing apparatus; and

a software module executed by said data processing apparatus, said module and said data processing apparatus being operable in combination with one another to;

apply a plurality of sensor measurement inputs that corresponds to at least one sensor range to a sensing means;

convert a plurality of electrical signals generated by said pressure means into a plurality of digital bit counts; and

calibrate said plurality of digital bit counts in order to generate a plurality of calibration coefficient.

17. The system of claim 16, wherein said module and said data processing apparatus are further operable in combination with one another to:

determine if said plurality of calibration coefficients corresponds to a transition point wherein said transition point being recorded into an ASIC; and

set at least one resolution and at least one gain factor corresponds to said at least one sensor range.

18. The system of claim 16, wherein said pressure sensing element further comprises a piezoresistive Wheatstone bridge.

19. The system of claim 16, wherein a plurality of digital bit counts can be generated utilizing an analog-to-digital (A/D) interface.

20. The system of claim 16, wherein said transition point can be stored in an EEPROM fabricated to suit ASIC provide at least one resolution.

21. The system of claim 16, wherein said input resolution effectively changes said gain factor thereby outputting signals with a different slope.