Transducer system with configurable acoustic overload point
A MEMS transducer system has a transducer configured to convert a received signal into an output signal for forwarding by a transducer output port, and an integrated circuit having an IC input in communication with the transducer output port. The IC input is configured to receive an IC input signal produced as a function of the output signal. The system also has a dividing element coupled between the IC input and the transducer output port. The dividing element is configured to selectively attenuate one or more signals into the IC input to at least in part produce the IC input signal. Other implementations may couple a feedback loop to the ground of the transducer (similar to bootstrapping), or pick off voltages at specific portions of the transducer.
1. A MEMS transducer system comprising:
a transducer comprising a plurality of sense members configured to independently move in response to a pressure signal to produce a plurality of member signals, the transducer further including an output port for forwarding at least one of the member signals;
an integrated circuit having an IC input in electric communication with the transducer output port, the IC input being configured to receive an IC input signal that is produced as a function of the at least one of the member signals; and
an attenuator coupled between the IC input and the transducer output port, the attenuator being electrically coupled with at least one of the sense members, the attenuator being configured to selectively electrically couple fewer than all of the member signals with the IC input, the attenuator being selectably actuatable and configured to selectively attenuate one or more member signals into the IC input to at least in part produce an attenuated IC input signal, the attenuator being integral with the integrated circuit or separate from the integrated circuit.
2. The MEMS transducer system of claim 1 wherein the attenuator comprises a dividing element coupled between the IC input and the transducer output port, the dividing element being selectably actuatable.
3. The MEMS transducer system of claim 2 wherein the dividing element includes at least one attenuation branch, each attenuation branch having a switch and a capacitance in series with the switch.
4. The MEMS transducer system of claim 2 wherein the dividing element includes a plurality of attenuation branches that each have a switch and a capacitance in series with the switch.
5. The MEMS transducer system of claim 4 wherein the integrated circuit has a mode pin configured to actuate at least one attenuation branch in response to receipt of a first signal, and to disable the at least one attenuation branch in response to receipt of a second signal.
6. The MEMS transducer system of claim 4 further comprising memory storing information for selectably actuating prescribed attenuation branches.
7. The MEMS transducer system of claim 1 wherein the transducer comprises at least one of a microphone, speaker, accelerometer, gyroscope, inertial sensor, tilt sensor, chemical sensor, pressure sensor, and/or ultrasonic transducer.
8. The MEMS transducer system of claim 1 wherein the transducer comprises a piezoelectric MEMS microphone.
9. The MEMS transducer system of claim 1 wherein the integrated circuit comprises an application specific integrated circuit with an operational amplifier having a non-inverting input and an op-amp output, the IC input being coupled with the non-inverting input, the IC having an output coupled with the op-amp output.
10. The MEMS transducer system of claim 1 wherein a node connects the IC input and transducer output port, the attenuator being coupled with the node and electrically in parallel with the transducer output port.
11. The MEMS transducer system of claim 1 wherein the transducer and integrated circuit each are formed on different dies.
12. A MEMS transducer system comprising:
a MEMS transducer configured to convert a received signal into a transducer signal, the transducer further including a transducer ground node;
an integrated circuit in communication with the MEMS transducer to receive the transducer signal, the integrated circuit having an output and configured to process the received transducer signal to produce an IC output signal at the output,
the transducer ground node being coupled with the integrated circuit output to receive the IC output signal.
13. The MEMS transducer of claim 12 further having a feedback segment electrically connecting the output of the integrated circuit with the transducer ground node.
14. The MEMS transducer of one claim 13 wherein the feedback segment has an amplifier configured to selectively amplify or attenuate the IC output signal.
15. The MEMS transducer system of claim 12 wherein the MEMS transducer comprises at least one of a microphone, speaker, accelerometer, gyroscope, inertial sensor, tilt sensor, chemical sensor, pressure sensor, and/or ultrasonic transducer.
16. The MEMS transducer system of claim 12 wherein the MEMS transducer comprises a piezoelectric MEMS microphone.
17. The MEMS transducer system of claim 12 wherein the MEMS transducer and integrated circuit each are part of the same die.
18. The MEMS transducer system of claim 12 wherein the MEMS transducer and integrated circuit each are formed on different dies, the transducer system further including a package forming a chamber containing the MEMS transducer and the integrated circuit.