SENSORS FOR MEASURING TEMPERATURE, PRESSURE TRANSDUCERS INCLUDING TEMPERATURE SENSORS AND RELATED ASSEMBLIES AND METHODS

1 . A quartz resonator pressure transducer for use in a subterranean borehole, comprising:

a pressure housing comprising at least one chamber;

an electronics housing comprising an electronics assembly;

a quartz pressure sensor in communication with the at least one chamber and for measuring pressure of a fluid disposed within the at least one chamber, wherein the electronics assembly is configured to drive the quartz pressure sensor at a selected frequency and to sense a pressure-related frequency response from the quartz pressure sensor; and

an electronic temperature sensor electrically coupled to the electronics assembly and configured to output a temperature signal to the electronics assembly.

2 . The quartz resonator pressure transducer of claim 1 , wherein the temperature signal comprises a frequency signal.

3 . The quartz resonator pressure transducer of claim 1 , wherein the electronic temperature sensor comprises a silicon temperature sensor.

4 . The quartz resonator pressure transducer of claim 3 , wherein the electronic temperature sensor comprises a proportional to absolute temperature (PTAT) current generator configured to generate a PTAT current.

5 . The quartz resonator pressure transducer of claim 4 , wherein the electronic temperature sensor further comprises a constant current generator configured to generate a constant current.

6 . The quartz resonator pressure transducer of claim 5 , wherein the electronic temperature sensor comprises a relaxation oscillator that is coupled to each of the PTAT current generator and the constant current generator, the relaxation oscillator configured to generate an output signal responsive to a complementary to absolute temperature current comprising a difference between the constant current and the PTAT current.

7 . The quartz resonator pressure transducer of claim 5 , wherein the electronic temperature sensor has a trip point for charging and discharging a capacitor, the trip point responsive to the constant current.

8 . The quartz resonator pressure transducer of claim 1 , further comprising a pressure bulkhead for separating the pressure housing from the electronics housing, wherein the electronic temperature sensor is at least partially embedded in the pressure bulkhead.

9 . The quartz resonator pressure transducer of claim 1 , wherein both the quartz pressure sensor and the electronic temperature sensor are positioned to be at least partially disposed within the fluid disposed within the at least one chamber.

10 . The quartz resonator pressure transducer of claim 1 , wherein the electronic temperature sensor is disposed in the electronics housing.

11 . The quartz resonator pressure transducer of claim 10 , wherein the electronic temperature sensor is disposed on an integrated circuit of the electronics assembly in the electronics housing.

12 . The quartz resonator pressure transducer of claim 10 , further comprising a quartz reference sensor positioned between the electronic temperature sensor and the quartz pressure sensor.

13 . The quartz resonator pressure transducer of claim 1 , further comprising:

a quartz reference sensor; and

a pressure bulkhead for separating the pressure housing from the electronics housing, wherein the electronic temperature sensor is positioned between the quartz reference sensor and the quartz pressure sensor.

14 . The quartz resonator pressure transducer of claim 13 , wherein the electronic temperature sensor and the quartz reference sensor are positioned on a first side of the pressure bulkhead and the quartz pressure sensor is positioned on a second side of the pressure bulkhead opposing the first side.

15 . The quartz resonator pressure transducer of claim 14 , wherein the electronic temperature sensor and the quartz reference sensor are each disposed in a transistor outline (TO) package.

16 . The quartz resonator pressure transducer of claim 15 , wherein the transistor outline (TO) package of the electronic temperature sensor has a volume that is less than a volume of the transistor outline (TO) package of the quartz reference sensor.

17 . The quartz resonator pressure transducer of claim 13 , wherein the quartz reference sensor is positioned on a first side of the pressure bulkhead and the quartz pressure sensor and the electronic temperature sensor are positioned on a second side of the pressure bulkhead opposing the first side.

18 . A temperature sensor, comprising:

a constant current generator configured to generate a constant current (I CONST );

a proportional to absolute temperature (PTAT) current generator configured to generate a PTAT current; and

a relaxation oscillator operably coupled to the constant current generator and the PTAT current generator, and configured to charge and discharge a capacitor responsive to a complementary to absolute temperature current comprising a difference between the constant current and the PTAT current.

19 . The temperature sensor of claim 18 , wherein the relaxation oscillator includes a comparator having a first input and a second input, the first input configured to receive a voltage on the capacitor, and the second input configured to receive a trip voltage.

20 . The temperature sensor of claim 19 , wherein the relaxation oscillator is configured such that:

during a first phase of the relaxation oscillator, the constant current sources current to the capacitor and the PTAT current sinks current from the capacitor; and

during a second phase of the relaxation oscillator, the PTAT current sources current to the capacitor and the constant current sinks current from the capacitor.

21 . The temperature sensor of claim 19 , wherein relaxation oscillator is configured to raise the trip voltage during a first phase of the relaxation oscillator, and lower the trip voltage during a second phase of the relaxation oscillator.

22 . A pressure transducer, comprising:

at least one pressure sensor; and

the temperature sensor of claim 18 .

23 . A method of monitoring pressure in a subterranean borehole, comprising:

resonating a quartz pressure sensor under an applied fluid pressure at at least one frequency with an electronics assembly of a pressure transducer;

monitoring a frequency output of the quartz pressure sensor with the electronics assembly;

resonating a quartz reference sensor at at least one frequency with the electronics assembly;

monitoring a frequency output of the quartz reference sensor with the electronics assembly;

powering an electronic temperature sensor with the electronics assembly; and

monitoring a frequency output of the electronic temperature sensor with the electronics assembly.

24 . The method of claim 23 , further comprising measuring a temperature within the pressure transducer with a proportional to absolute temperature (PTAT) sensor.

25 . The method of claim 23 , further comprising temperature-compensating the monitored frequency output of the quartz pressure sensor with the electronics assembly using the frequency output of the electronic temperature sensor.