A tunable filter is described where the frequency response as well as bandwidth and transmission loss characteristics can be dynamically altered, providing improved performance for transceiver front-end tuning applications. The rate of roll-off of the frequency response can be adjusted to improve performance when used in duplexer applications. The tunable filter topology is applicable for both transmit and receive circuits. A method is described where the filter characteristics are adjusted to account for and compensate for the frequency response of the antenna used in a communication system.

For example, an averaging circuit includes first to third capacitors and a controller. The controller causes a first first-stage average voltage to be applied to a first capacitor, the first first-stage average voltage being an average of a first voltage applied to the first capacitor and a second voltage applied to a second capacitor, causes a second first-stage average voltage to be applied to the second capacitor, the second first-stage average voltage being an average of a third voltage applied to the second capacitor and a fourth voltage applied to a third capacitor, and causes a first second-stage average voltage to be applied to the first capacitor, the first second-stage average voltage being an average of the first and second first-stage average voltages applied to the first and second capacitors.

An ultra-low-power receiver includes a low-noise amplifier configured to receive an input analog signal and generate an amplified signal and a mixer electrically coupled to the low-noise amplifier. The mixer is configured to convert said amplified signal into an intermediate frequency signal. A progressively reduced intermediate frequency filter is configured to process the intermediate frequency signal from the mixer in discrete time.

An example SC integrator can include first and second sampling capacitors, an amplifier, an integrating capacitor, coupled at least to an output of the amplifier, and a switching arrangement. The SC integrator can be configured for adding (i.e., integrating in the integrating capacitor) sign-inverted samples of a flicker noise of the amplifier at one or more cycles of a master clock and can be configured for keeping the time distance/delay between those samples relatively small across a range of master clock frequencies.

A sensor device includes: first sensors; second sensors which form capacitances with the first sensors; a sensor transmitter connected to the first sensors, where the sensor transmitter supplies driving signals to the first sensors; and a sensor receiver connected to the second sensors, where the sensor receiver receives sensing signals from the second sensors, and the sensor receiver includes a band pass filter which filters the sensing signals. The band pass filter includes: a first integrator including a first amplifier; a first high pass filter converter connected to a first input terminal, a second input terminal and a first output terminal of the first amplifier, where the first high pass filter converter time-divisionally provides N high pass filter conversion paths; and a first gain auxiliary component connected to the first input terminal and the first output terminal of the first amplifier while the first integrator performs an integral function.

A switched capacitor low-pass filter. The filter includes a plurality of switched capacitors, and a plurality of resistors. The resistors increase the slope of the roll-off of the filter, reduce DC gain variations across corners, and minimize the frequency variation across corners. In some embodiments, the clock signal used to control the switched capacitor filters has a duty cycle differing from 50%, to improve the frequency response of the filter.

A delta-sigma modulator includes a first integrator configured to integrate a sum of an input signal and a first feedback signal, a second integrator configured to integrate a sum of an output value of the first integrator and a second feedback signal, a first FIR filter circuit configured to perform a first FIR filtering on an output modulation signal and a delay modulation signal and feeds back the signals to stage prior to the first integrator, and a second FIR filter circuit configured to perform a second FIR filtering on the output modulation signal and the delay modulation signal and feeds back the signals to a stage prior to the second integrator.

A system may include an input for receiving an input signal, an output for generating an output signal, a capacitor coupled between the input and the output, a variable resistor coupled to the output and having a plurality of modes including a first mode in which the variable resistor has a first resistance and a second mode in which the variable resistor has a second resistance, and control circuitry configured to determine a difference between the input signal and the output signal and switch between modes of the plurality of modes when the difference is less than a predetermined threshold.

The present disclosure relates to a head-wearable hearing device which comprises a magnetic inductance antenna having a predetermined resonance period for receipt of wireless data signals and a switched capacitor DC-DC converter configured for converting a DC input voltage into a higher or lower DC output voltage in accordance with a clock signal. The charge pump circuit is configured to charge an output capacitor by output current pulses where the output current pulses at least comprise first and second consecutive output current pulses having a mutual pulse delay corresponding to substantially one-half of the predetermined resonance period of the magnetic inductance antenna.

A physical quantity detection device includes a switched capacitor filter circuit having a first sample-and-hold circuit adapted to sample and hold a first signal, which is based on an output signal of a physical quantity detection element, an amplifier circuit to which an output signal of the first sample-and-hold circuit is input, and a first switched capacitor circuit to which a first output signal of the amplifier circuit is input, wherein an output signal of the first switched capacitor circuit is input to the amplifier circuit, and an A/D conversion circuit adapted to perform an A/D conversion on an output signal of the switched capacitor filter circuit.