Abstract: A device is provided. The device includes: a sensor adapted to receive an acoustic wave and generate an electrical signal in response to receipt of the acoustic wave; clock frequency detection circuitry adapted to receive a clock signal, detect a frequency of the clock signal and generate information representative of the frequency; and digital filter circuitry coupled to the clock frequency detection circuitry. The digital filter circuitry is adapted to: receive the clock signal and the information representative of the frequency; access a first set of one or more digital filter coefficient values; and selectively change the first set of the one or more digital filter coefficient values to a second set of one or more digital filter coefficient values based on the information representative of the frequency, wherein the one or more digital filter coefficient values are included within a plurality of digital filter coefficient values.

Abstract: Methods and apparatus automatically cancel or attenuate an unwanted signal (such as low frequencies from wind buffets) from, and/or control frequency response of, a condenser microphone, or control the effective condenser microphone sensitivity before the signal reaches an ASIC or other processing circuit. As a result, the maximum amplitude signal seen by the processing circuit is limited, thereby preventing overloading the input of the processing circuit. Remaining (wanted) frequencies can be appropriately amplified to reduce the noise burden on further processing circuits. A corrective signal is applied to a bias terminal of the condenser microphone to cancel the unwanted signal. Optionally or alternatively, a controllable impedance is connected to a line that carries the signal generated by the MEMS microphone, so as to attenuate unwanted portions of the signal.

Abstract: A device is provided. The device includes: a sensor adapted to receive an acoustic wave and generate an electrical signal in response to receipt of the acoustic wave; clock frequency detection circuitry adapted to receive a clock signal, detect a frequency of the clock signal and generate information representative of the frequency; and digital filter circuitry coupled to the clock frequency detection circuitry. The digital filter circuitry is adapted to: receive the clock signal and the information representative of the frequency; access a first set of one or more digital filter coefficient values; and selectively change the first set of the one or more digital filter coefficient values to a second set of one or more digital filter coefficient values based on the information representative of the frequency, wherein the one or more digital filter coefficient values are included within a plurality of digital filter coefficient values.

Abstract: A switch control circuit monitors a signal produced by a MEMS or other capacitor microphone. When a criterion is met, for example when the amplitude of the monitored signal exceeds a threshold or the monitored signal has been clipped or analysis of the monitored signal indicates clipping is imminent or likely, the switch control circuit operates one or more switches so as to selectively connect one or more capacitors to a signal line from the microphone, i.e., so as to connect a selected capacitance to the signal line to attenuate the signal from the microphone and, therefore, avoid clipping. The switches may be MOSFET, MEMS or other types of switches co-located with the microphone in a common semiconductor package. Similarly, the capacitors, a circuit that processes the signals from the microphone and/or the switch control circuit may be co-located with the microphone in a common semiconductor package.

Abstract: The present invention relates to a DC bias voltage circuit comprising a DC bias voltage generator adapted to supply a first DC voltage. A low-pass filter has an input operatively coupled to the first DC voltage to produce a second DC voltage at a low-pass filter output. The low-pass filter comprises an adjustable switched capacitor resistor setting a cut-off frequency of the low-pass filter and a controller is adapted to controlling a resistance of the adjustable switched capacitor resistor.

Abstract: Methods and apparatus automatically cancel or attenuate an unwanted signal (such as low frequencies from wind buffets) from, and/or control frequency response of, a condenser microphone, or control the effective condenser microphone sensitivity before the signal reaches an ASIC or other processing circuit. As a result, the maximum amplitude signal seen by the processing circuit is limited, thereby preventing overloading the input of the processing circuit. Remaining (wanted) frequencies can be appropriately amplified to reduce the noise burden on further processing circuits. A corrective signal is applied to a bias terminal of the condenser microphone to cancel the unwanted signal. Optionally or alternatively, a controllable impedance is connected to a line that carries the signal generated by the MEMS microphone, so as to attenuate unwanted portions of the signal.

Abstract: Methods and apparatus automatically cancel or attenuate an unwanted signal (such as low frequencies from wind buffets) from, and/or control frequency response of, a condenser microphone, or control the effective condenser microphone sensitivity before the signal reaches an ASIC or other processing circuit. As a result, the maximum amplitude signal seen by the processing circuit is limited, thereby preventing overloading the input of the processing circuit. Remaining (wanted) frequencies can be appropriately amplified to reduce the noise burden on further processing circuits. A corrective signal is applied to a bias terminal of the condenser microphone to cancel the unwanted signal. Optionally or alternatively, a controllable impedance is connected to a line that carries the signal generated by the MEMS microphone, so as to attenuate unwanted portions of the signal.

Abstract: A control circuit monitors a signal produced by a MEMS or other capacitor microphone. When a criterion is met, for example when the amplitude of the monitored signal exceeds a threshold or the monitored signal has been clipped or analysis of the monitored signal indicates clipping is imminent or likely, the control circuit automatically adjusts a bias voltage applied to the capacitor microphone, thereby adjusting sensitivity of the capacitor microphone.

Abstract: A switch control circuit monitors a signal produced by a MEMS or other capacitor microphone. When a criterion is met, for example when the amplitude of the monitored signal exceeds a threshold or the monitored signal has been clipped or analysis of the monitored signal indicates clipping is imminent or likely, the switch control circuit operates one or more switches so as to selectively connect one or more capacitors to a signal line from the microphone, i.e., so as to connect a selected capacitance to the signal line to attenuate the signal from the microphone and, therefore, avoid clipping. The switches may be MOSFET, MEMS or other types of switches co-located with the microphone in a common semiconductor package. Similarly, the capacitors, a circuit that processes the signals from the microphone and/or the switch control circuit may be co-located with the microphone in a common semiconductor package.

Abstract: Methods and apparatus automatically cancel or attenuate an unwanted signal (such as low frequencies from wind buffets) from, and/or control frequency response of, a condenser microphone, or control the effective condenser microphone sensitivity before the signal reaches an ASIC or other processing circuit. As a result, the maximum amplitude signal seen by the processing circuit is limited, thereby preventing overloading the input of the processing circuit. Remaining (wanted) frequencies can be appropriately amplified to reduce the noise burden on further processing circuits. A corrective signal is applied to a bias terminal of the condenser microphone to cancel the unwanted signal. Optionally or alternatively, a controllable impedance is connected to a line that carries the signal generated by the MEMS microphone, so as to attenuate unwanted portions of the signal.

Abstract: A switch control circuit monitors a signal produced by a MEMS or other capacitor microphone. When a criterion is met, for example when the amplitude of the monitored signal exceeds a threshold or the monitored signal has been clipped or analysis of the monitored signal indicates clipping is imminent or likely, the switch control circuit operates one or more switches so as to selectively connect one or more capacitors to a signal line from the microphone, i.e., so as to connect a selected capacitance to the signal line to attenuate the signal from the microphone and, therefore, avoid clipping. The switches may be MOSFET, MEMS or other types of switches co-located with the microphone in a common semiconductor package. Similarly, the capacitors, a circuit that processes the signals from the microphone and/or the switch control circuit may be co-located with the microphone in a common semiconductor package.

Abstract: The present invention relates to a DC bias voltage circuit comprising a DC bias voltage generator adapted to supply a first DC voltage. A low-pass filter has an input operatively coupled to the first DC voltage to produce a second DC voltage at a low-pass filter output. The low-pass filter comprises an adjustable switched capacitor resistor setting a cut-off frequency of the low-pass filter and a controller is adapted to controlling a resistance of the adjustable switched capacitor resistor.

Abstract: A charge/discharge control circuit for controlling current through an input/output audio device includes a first voltage reference; a second voltage reference and a waveform generation circuit responsive to the first and second voltage references for generating a multi-stage waveform profile which is approximately an inaudible waveform for suppressing audible artifacts in the input/output device.

Abstract: A control circuit monitors a signal produced by a MEMS or other capacitor microphone. When a criterion is met, for example when the amplitude of the monitored signal exceeds a threshold or the monitored signal has been clipped or analysis of the monitored signal indicates clipping is imminent or likely, the control circuit automatically adjusts a bias voltage applied to the capacitor microphone, thereby adjusting sensitivity of the capacitor microphone.

Abstract: A switched capacitor system with output glitch reduction step charges the switched capacitor by switching it to a first voltage level in a first phase, to an intermediate voltage level of a pre-charge node in a pre-charge phase and to the voltage level of the output node of the amplifier stage in a settling phase; the pre-charge node can be implemented at the input of the amplifier stage, the output of a preceding stage or at any other pre-existing suitable node in the amplifier system.

Abstract: A switch control circuit monitors a signal produced by a MEMS or other capacitor microphone. When a criterion is met, for example when the amplitude of the monitored signal exceeds a threshold or the monitored signal has been clipped or analysis of the monitored signal indicates clipping is imminent or likely, the switch control circuit operates one or more switches so as to selectively connect one or more capacitors to a signal line from the microphone, i.e., so as to connect a selected capacitance to the signal line to attenuate the signal from the microphone and, therefore, avoid clipping. The switches may be MOSFET, MEMS or other types of switches co-located with the microphone in a common semiconductor package. Similarly, the capacitors, a circuit that processes the signals from the microphone and/or the switch control circuit may be co-located with the microphone in a common semiconductor package.

Abstract: A system and method for mutually charging switched capacitors in a switched capacitor system includes operating first and second sets of output switches during separate phases; operating first and second sets of input switches during separate phases but after the output switches are operated; and connecting the switched capacitors together after the output switches are operated but before the input switches are operated to enable them to share charge with each other toward a common mode voltage after the output switches are operated but before the input switches are operated.