Piezoelectric mems device for producing a signal indicative of detection of an acoustic stimulus

1. A device comprising:

a sensor; and

a first circuit configured to detect when an input stimulus to the sensor satisfies one or more detection criteria, and further configured to produce a signal upon detection that causes adjustment of performance of the device, wherein the first circuit is configured to reduce its power level following detection, relative to a power level of the first circuit prior to detection; and

a second circuit for processing input following detection, wherein the second circuit is configured to increase its power level following detection, relative to a power level of the second circuit prior to detection.

2. The device of claim 1 , wherein the sensor comprises an acoustic sensor.

3. The device of claim 1 , wherein the input stimulus comprises an acoustic input stimulus.

4. The device of claim 1 , wherein the input comprises an acoustic input.

5. The device of claim 1 , wherein the signal causes adjustment of performance of the device by causing an external processor to transmit an instruction to the device to increase the power level of the second circuit, relative to the power level of the second circuit prior to detection.

6. The device of claim 1 , wherein the signal causes adjustment of performance of the device by causing the device to increase the power level of the second circuit, relative to the power level of the second circuit prior to detection.

7. The device of claim 1 , wherein the second circuit is substantially powered off prior to detection.

8. The device of claim 1 , wherein the device is configured to receive a signal from a processor external to the device, with the signal being for powering off the first circuit and for powering on the second circuit.

9. The device of claim 1 , wherein the device is configured to receive a signal from a processor external to the device, with the signal being for reducing a power level of the first circuit, relative to a power level of the first circuit prior to detection, and with the signal further being for increasing the power level of the second circuit, relative to the power level of the second circuit prior to detection.

10. The device of claim 1 , further comprising:

a third circuit with logic for reducing a power level of the first circuit, relative to a power level of the first circuit prior to detection, and for increasing the power level of the second circuit, relative to the power level of the second circuit prior to detection.

11. The device of claim 1 , wherein the device includes a packaged device for mounting on another circuit, wherein the packaged device includes a substrate for mounting the sensor, the first circuit and the second circuit, and wherein the packaged device includes a housing portion.

12. The device of claim 1 , wherein the device includes a piezoelectric device.

13. The device of claim 1 , wherein the device includes a microphone or a microelectromechanical systems (MEMS) microphone.

14. The device of claim 1 , further comprising:

a pad configured to transmit, to an external processor, a signal that specifies that the input stimulus to the sensor satisfies at least one of the one or more detection criteria.

15. The device of claim 1 , further comprising:

a pad configured to receive, from an external processor, a signal that causes the device to switch from a first mode to a second mode.

16. The device of claim 15 , wherein the first mode comprises a mode in which the first circuit is substantially powered on and the second circuit is substantially powered off.

17. The device of claim 15 , wherein the second mode comprises a mode in which the second circuit is substantially powered on and the first circuit is substantially powered off.

18. The device of claim 1 , wherein the device is configured to switch from a first mode to a second mode, following detection, wherein the first mode comprises a mode in which the first circuit is substantially powered on and the second circuit is substantially powered off, wherein the second mode comprises a mode in which the second circuit is substantially powered on and the first circuit is substantially powered off.

19. The device of claim 18 , further comprising:

a switch configured to switch from the first mode to the second mode in response to receipt of an instruction from a third circuit of the device.

20. One or more machine-readable hardware storage devices comprising instructions that are executable by a device to perform one or more operations comprising:

detecting, by a first circuit, when an input stimulus to a sensor satisfies one or more detection criteria;

producing a signal upon detection that causes adjustment of performance of the device by causing the first circuit to reduce its power level, relative to a power level of the first circuit prior to detection and causing a second circuit of the device to increase its power level, relative to a power level of the second circuit prior to detection; and

processing input to the device using the second circuit with the increased power level.

21. A method performed by a device, comprising:

detecting, by a first circuit, when an input stimulus to a sensor of a device satisfies one or more detection criteria;

producing a signal upon detection that causes adjustment of performance of the device by causing the first circuit to reduce its power level, relative to a power level of the first circuit prior to detection and causing a second circuit of the device to increase its power level, relative to a power level of the second circuit prior to detection; and

processing input to the device using the second circuit with the increased power level.