An electronic driving circuit for a microfluidic device, having a number of synchronized driving stages to generate a respective driving signal for each electrode or group of electrodes of the microfluidic device, the driving signals having a desired amplitude, frequency and phase-shift. Each driving stage has a switching-mode amplifier stage to receive a clock signal and a target signal and to generate, at an output thereof, an output signal defining a respective driving signal. The amplifier stage has: a switching module, coupled to a first internal node and controlled by the clock signal for selectively bringing the first internal node to a control signal; a filter module, coupled between the first internal node and the output, to provide the output signal; and a feedback module.

An electronic driving circuit for a microfluidic device, having a number of synchronized driving stages to generate a respective driving signal for each electrode or group of electrodes of the microfluidic device, the driving signals having a desired amplitude, frequency and phase-shift. Each driving stage has a switching-mode amplifier stage to receive a clock signal and a target signal and to generate, at an output thereof, an output signal defining a respective driving signal. The amplifier stage has: a switching module, coupled to a first internal node and controlled by the clock signal for selectively bringing the first internal node to a control signal; a filter module, coupled between the first internal node and the output, to provide the output signal; and a feedback module.

A hearing prosthesis circuit includes a power source, a first amplifier coupled to the power source, and a second amplifier coupled to the power source. The circuit also includes a stimulation component coupled to the first amplifier and the second amplifier. The stimulation component is configured to provide an output in accordance with an electrical signal that includes audio data. Further, the circuit includes a controller coupled to the first amplifier and the second amplifier. The controller is operable in accordance with a first operational setting to use the first amplifier to provide the electrical signal to the stimulation component and the controller is also operable in accordance with a second operational setting to use the second amplifier to provide the electrical signal to the stimulation component. Generally, the first amplifier provides greater signal amplification of the audio data than the second amplifier.

In accordance with an embodiment, a wireless power transmitter includes a charging surface, a transmitting antenna configured to generate an electromagnetic field extending above the charging surface, a sensing array disposed between the transmitting antenna and the charging surface, and a controller coupled to the sensing array. The sensing array includes a plurality of sensors. Each sensor of the plurality of sensors is configured to generate a respective signal indicative of a strength of the electromagnetic field. The controller is configured to detect a presence of a metallic object, other than a receiving antenna of a power receiver, in the electromagnetic field based on the respective signal generated by one or more sensors of the plurality of sensors.

In accordance with an embodiment, a wireless power transmitter includes a charging surface, a transmitting antenna configured to generate an electromagnetic field extending above the charging surface, a sensing array disposed between the transmitting antenna and the charging surface, and a controller coupled to the sensing array. The sensing array includes a plurality of sensors. Each sensor of the plurality of sensors is configured to generate a respective signal indicative of a strength of the electromagnetic field. The controller is configured to detect a presence of a metallic object, other than a receiving antenna of a power receiver, in the electromagnetic field based on the respective signal generated by one or more sensors of the plurality of sensors.

A semiconductor MOS device having an epitaxial layer with a first conductivity type formed by a drain region and by a drift region. The drift region accommodates a plurality of first columns with a second conductivity type and a plurality of second columns with the first conductivity type, the first and second columns alternating with each other and extending on the drain region. Insulated gate regions are each arranged on top of a respective second column; body regions having the second conductivity type extend above and at a distance from a respective first column, thus improving the output capacitance C.sub.ds of the device, for use in high efficiency RF applications.

An amplifier for headphones including a current digital-to-analog converter (DAC) configured to output a current based on a digital audio input signal, an output electrically connected to a speaker and configured to output an output signal to the speaker, and a pulse width modulation (PWM) loop configured to receive an error signal, the error signal based on a difference between the current from the current DAC and a current of the output signal, and generate the output signal based on the error signal. The PWM loop includes an analog-to-digital converter (ADC) configured to receive an analog signal based on the current from the current DAC and output a digital signal representing the analog signal, and an encoder configured to receive the digital signal and output a pulse having a width based on the analog signal.

The invention relates to a method for operating a class-D amplifier (2) for an audio signal (4), which class-D amplifier contains an output stage (10) and a signal-processing unit (12) in a signal path (6), wherein a voltage (U) of at least two magnitudes (U1, U2) is provided for the output stage (10), a voltage requirement (B) of the output stage (10) for the audio signal (4) is predictively determined from the audio signal (4) at a measurement location (14) before the signal-processing unit (12), a magnitude (U1, U2) that is minimally sufficient for the voltage requirement (B) is selected on the basis of the voltage requirement (B) and said magnitude is applied to the output stage (10) before the amplification. A class-D amplifier (2) for an audio signal (4), having a signal path (6), which has an output stage (10) and a signal-processing unit (12), contains a voltage source (16) for the output stage (10) having a voltage (U) of at least two magnitudes (U1, U2), a measurement location (14) before the signal-processing unit (12), and a control and evaluation unit (18) for predictively determining a voltage requirement (B) for the output stage (10) for the proper amplification of the audio signal (4) from the audio signal (4) at the measurement location (14), wherein the control and evaluation unit (18) selects a magnitude (U1, U2) that is minimally sufficient for the voltage requirement (B) on the basis of the voltage requirement (B) and applies said magnitude to the output stage (10) before the amplification.

The disclosure presents a method and an amplifier system for minimizing variation in an acoustical signal caused by variation in gain of an amplifier, comprising a battery for providing a supply voltage to the amplifier, a digital signal processor for providing the acoustical signal to the amplifier, a controller unit receiving an enablement signal when the supply voltage is in an offset mode, and based on the enablement signal requesting a measured voltage during a time period, and a first analog-to-digital converter configured for measuring the supply voltage to the amplifier when receiving the request from the controller unit or the first analog-to-digital converter is configured for measuring the supply voltage to the amplifier continuously, and where variations in the measured voltage relates to variations in the supply voltage during the time period. Furthermore, the controller unit is configured to predict offset modes (i.e. changes) in the supply voltage based on the enablement signals and a fitting of the measured voltages, and wherein the controller unit is configured to generate a compensating signal based on the fitting and transmit the compensating signal to the digital signal processor, the digital signal processor is then configured to minimize variation in the acoustical signal at the output of the amplifier by compensating the variation in gain of the amplifier based on the compensating signal.

An amplifier comprising a gain stage with a feedback network comprising two ports between which at least three capacitors are connected in series and between each pair of capacitors a resistor is connected to a predetermined voltage. The gain stage is provided in a feedback loop over a primary amplifier.