A method of detecting defects in a high impedance network of a MEMs microphone sensor interface circuit. The method includes adding a high-voltage reset switch to a high-voltage high impedance network, closing the high-voltage reset switch during a start-up phase of the MEMs microphone sensor interface circuit, simultaneously closing a low-voltage reset switch of a low-voltage high impedance network during the start-up phase, simultaneously opening the high-voltage reset switch and the low-voltage reset switch at the end of the start-up phase, and detecting a defect in the high-voltage high impedance network or the low-voltage high impedance network immediately after opening the high-voltage reset switch and the low-voltage reset switch.

A method of detecting defects in a high impedance network of a MEMs microphone sensor interface circuit. The method includes adding a high-voltage reset switch to a high-voltage high impedance network, closing the high-voltage reset switch during a start-up phase of the MEMs microphone sensor interface circuit, simultaneously closing a low-voltage reset switch of a low-voltage high impedance network during the start-up phase, simultaneously opening the high-voltage reset switch and the low-voltage reset switch at the end of the start-up phase, and detecting a defect in the high-voltage high impedance network or the low-voltage high impedance network immediately after opening the high-voltage reset switch and the low-voltage reset switch.

An acoustic sensor adapted to convert acoustic vibration to a change in an electrostatic capacitance to detect the acoustic vibration is provided. The acoustic sensor includes a semiconductor substrate, a back plate including a fixed plate arranged to face a surface of the semiconductor substrate, and a fixed electrode film arranged on the fixed plate, and a vibrating electrode film arranged to face the back plate with a space formed therebetween. The vibrating electrode film includes a plate-like vibrating member that vibrates in response to sound pressure. The vibrating electrode film is fixed to the back plate with a fixing unit thereof including one or more fixing portions each including a fixing protruding end that is arranged on a protruding end of a leg portion protruding from an edge of the vibrating member. The vibrating member has an edge portion surrounding at least a part of the fixing protruding end.

A self-testing electro-mechanical capacitive sensor system. The system includes an electro-mechanical capacitive sensor and a controller. The controller is configured to receive a signal to activate a test mode, and upon receiving the signal to activate the test mode: (a) apply a bias voltage step to the electro-mechanical capacitive sensor, (b) measure a corresponding deflection of a membrane of the electro-mechanical capacitive sensor for the bias voltage as a function of time, and repeat steps (a) and (b) for a plurality of magnitudes of the bias voltage to determine at least one performance parameter of the electro-mechanical capacitive sensor.

A self-testing electro-mechanical capacitive sensor system. The system includes an electro-mechanical capacitive sensor and a controller. The controller is configured to receive a signal to activate a test mode, and upon receiving the signal to activate the test mode: (a) apply a bias voltage step to the electro-mechanical capacitive sensor, (b) measure a corresponding deflection of a membrane of the electro-mechanical capacitive sensor for the bias voltage as a function of time, and repeat steps (a) and (b) for a plurality of magnitudes of the bias voltage to determine at least one performance parameter of the electro-mechanical capacitive sensor.

A micro-electro-mechanical system, MEMS, microphone assembly comprises an enclosure defining a first cavity, and a MEMS microphone arranged inside the first cavity. The microphone comprises a first die with bonding structures and a MEMS diaphragm, and a second die having an application specific integrated circuit, ASIC. The second die is bonded to the bonding structures such that a gap is formed between a first side of the diaphragm and the second die, with the gap defining a second cavity. The first side of the diaphragm is interfacing with the second cavity and a second side of the diaphragm is interfacing with the environment via an acoustic inlet port of the enclosure. The bonding structures are arranged such that pressure ventilation openings are formed that connect the first cavity and the second cavity.

A micro-electro-mechanical system, MEMS, microphone assembly comprises an enclosure defining a first cavity, and a MEMS microphone arranged inside the first cavity. The microphone comprises a first die with bonding structures and a MEMS diaphragm, and a second die having an application specific integrated circuit, ASIC. The second die is bonded to the bonding structures such that a gap is formed between a first side of the diaphragm and the second die, with the gap defining a second cavity. The first side of the diaphragm is interfacing with the second cavity and a second side of the diaphragm is interfacing with the environment via an acoustic inlet port of the enclosure. The bonding structures are arranged such that pressure ventilation openings are formed that connect the first cavity and the second cavity.

A charge amplifier circuit is provided. The charge amplifier circuit is couplable to a transducer that generates an electrical charge that varies with an external stimulus. The charge amplifier circuit includes an amplification stage having an input node, couplable to the transducer, and an output node. The amplification stage biases the input node at a first direct current (DC) voltage. The charge amplifier circuit includes a feedback circuit, which includes a feedback capacitor, electrically coupled between the input and output nodes of the amplification stage. The feedback circuit includes a resistor electrically coupled to the input node, and a level-shifter circuit, electrically coupled between the resistor and the output node. The level-shifter circuit biases the output node at a second DC voltage and as a function of a difference between the second DC voltage and a reference voltage.

A charge amplifier circuit is provided. The charge amplifier circuit is couplable to a transducer that generates an electrical charge that varies with an external stimulus. The charge amplifier circuit includes an amplification stage having an input node, couplable to the transducer, and an output node. The amplification stage biases the input node at a first direct current (DC) voltage. The charge amplifier circuit includes a feedback circuit, which includes a feedback capacitor, electrically coupled between the input and output nodes of the amplification stage. The feedback circuit includes a resistor electrically coupled to the input node, and a level-shifter circuit, electrically coupled between the resistor and the output node. The level-shifter circuit biases the output node at a second DC voltage and as a function of a difference between the second DC voltage and a reference voltage.

An ultrasonic actuation apparatus includes a piezoelectric transducer producing a first ultrasonic signal; a second transducer; and a platen, the platen being directly and/or acoustically coupled to the piezoelectric transducer and the second transducer. The second transducer may be a MEMS microphone. The second transducer is configured to receive the first ultrasonic signal at a first time, and a second ultrasonic signal at second time. The second ultrasonic signal has been modified from the first ultrasonic signal in correspondence with an object being in contact with the platen.