Pressure monitoring circuits and methods

1. A pressure monitoring system, comprising:

a pressure sensor to output an analog signal, wherein the analog signal has a signal level indicative of an ambient pressure sensed by the pressure sensor;

an analog-to-digital converter (ADC) to convert the analog signal to an N-bit digital signal representing one of 2 N unique output codes at a given time;

a control element to provide a control signal to the ADC, wherein the control signal causes the ADC to change from a first state in which the 2 N unique output codes are spaced over a first pressure range to a second state in which the 2 N unique output codes are spaced over a second pressure range.

2. The system of claim 1 , further comprising:

a variable gain stage between the pressure sensor and the ADC, wherein the control signal causes the variable gain stage to change from a first gain to a second gain, thereby causing the ADC to change from the first state to the second state, respectively.

3. The system of claim 2 , wherein the control element comprises a microcontroller to provide the control signal.

4. The system of claim 1 , wherein the control element comprises a comparator to compare the analog signal with a pressure threshold, and wherein the control signal is based on the comparison.

5. The system of claim 1 , further comprising:

a compensation module to apply a first plurality of compensation parameters during the first state and to apply a second plurality of compensation parameters during the second state, wherein the first and second plurality of compensation parameters account for non-linearities and other error contributors in the ADC and pressure sensor over the first and second pressure ranges, respectively.

6. The system of claim 1 , wherein the first pressure range falls entirely within the second pressure range.

7. The system of claim 1 , wherein the first pressure range only partially overlaps the second pressure range without falling entirely within the second pressure range.

8. The system of claim 1 , wherein the first pressure range and second pressure range are non-overlapping.

9. The system of claim 1 , wherein endpoints bounding the first pressure range are separated by a first difference that is greater than a second difference separating endpoints bounding the second pressure range.

10. The system of claim 9 , wherein neighboring unique output codes in the first pressure range are spaced apart by a first distance, and wherein neighboring unique output codes in the second pressure range are spaced apart by a second distance.

11. A method of pressure monitoring, comprising:

receiving an analog pressure signal corresponding to an ambient pressure;

providing a control signal to convert the analog pressure signal to an N-bit digital signal, wherein when the control signal in a first state the N-bit digital signal represents 2 N unique output codes that are spaced over a first pressure range and wherein when the control signal in a second state the N-bit digital signal represents 2 N unique output codes that are spaced over a second pressure range.

12. The method of claim 11 , further comprising:

upon receiving a request to monitor the ambient pressure, setting the control signal to the first state and storing a first digital pressure measurement and subsequently setting the control signal to the second state and storing a second digital pressure measurement.

13. The method of claim 12 , further comprising:

selecting one of the first and second digital pressure measurements and providing the selected digital pressure measurement in response to the request to measure the ambient pressure.

14. A pressure monitoring system, comprising:

a pressure sensor to output an analog signal, wherein the analog signal has a signal level indicative of an ambient pressure sensed by the pressure sensor;

an analog-to-digital converter (ADC) to convert the analog signal to an N-bit digital signal representing one of 2 N unique output codes at a given time;

a controller to provide a control signal to the ADC, wherein the control signal causes the ADC to change from a first state in which the ambient pressure is attempted to be measured in a first pressure range to a second state in which the ambient pressure is attempted to be measured in a second pressure range; and

a variable gain stage between the pressure sensor and the ADC, wherein the control signal causes the variable gain stage to change from a first gain to a second gain, thereby causing the ADC to change from the first state to the second state, respectively.

15. The system of claim 14 , wherein the first pressure range falls entirely within the second pressure range.

16. The system of claim 14 , wherein the first pressure range only partially overlaps the second pressure range without falling entirely within the second pressure range.

17. The system of claim 14 , wherein the first pressure range and second pressure range are non-overlapping.

18. A pressure monitoring system, comprising:

a pressure sensor to output an analog signal, wherein the analog signal has a signal level indicative of an ambient pressure sensed by the pressure sensor;

a comparator to compare the analog signal with a pressure threshold and provide a control signal based on the comparison; and

an analog-to-digital converter (ADC) to convert the analog signal to an N-bit digital signal, wherein the control signal causes the ADC to change from a first state in which the ambient pressure is attempted to be measured in a first pressure range to a second state in which the ambient pressure is attempted to be measured in a second pressure range.

19. The system of claim 18 , wherein the first pressure range falls entirely within the second pressure range.

20. The system of claim 18 , wherein the first pressure range only partially overlaps the second pressure range without falling entirely within the second pressure range.

21. The system of claim 18 , wherein the first pressure range and second pressure range are non-overlapping.