In accordance with a first aspect of the present disclosure, an active RC-type filter is provided, comprising: an input, an output and a signal path between said input and output; at least one capacitor bank and at least one resistor bank, wherein said capacitor bank and resistor bank are integrated into the signal path; wherein the resistor bank comprises a plurality of resistor ladders; wherein each one of said resistor ladders comprises a plurality of resistors connected in series; wherein each one of said resistors has an input node configured to be coupled selectively to the signal path through one of a plurality of controllable switches; and wherein said resistor ladders have output nodes directly coupled to each other and to the signal path. In accordance with a second aspect of the present disclosure, a corresponding method of implementing an active RC-type filter is conceived.

The embodiments of the present disclosure provide a method and system for adjusting a passband width of a filter. The method includes determining an initial passband width, controlling a filter according to the initial passband width to filter signals to be processed, and correcting the initial passband width according to a first frequency at which a peak spectrum line corresponding to the filtered signals is located.

According to at least one aspect, a filter network is provided. The filter network comprises: an active filter comprising an amplifier (e.g., an operational amplifier), wherein the active filter is configured to add at least one member selected from the group consisting of a pole and a zero to a transfer function of the filter network; a passive filter coupled to the active filter and configured to add at least one pole to the transfer function of the filter network; and a non-inverting amplifier (e.g., a voltage buffer) having an input coupled to the passive filter and an output coupled to the active filter.

A baseline restorer circuit including a controller; a sample control circuit arranged to receive an input voltage signal that is output from a circuit stage comprising an amplifier, and configured to capture a sample of the input voltage signal at a sampling time in response to receiving a control signal from the controller; an analogue processing stage to receive the sample and a constant baseline reference voltage and selectively process the sample to provide an output voltage; a transconductance stage to convert the output voltage to a compensation current and supply the compensation current to an input of the circuit stage; and a change detector to monitor if the input voltage signal changes during a time interval around the sampling time, and if no change is detected in the input voltage signal during the time interval, the controller is configured to control the analogue processing stage to process the sample.

According to one embodiment, a compact low-power receiver comprises first and second analog circuits connected by a digitally controlled interface circuit. The first analog circuit has a first direct-current (DC) offset and a first common mode voltage at an output, and the second analog circuit has a second DC offset and a second common mode voltage at an input. The digitally controlled interface circuit connects the output to the input, and is configured to match the first and second DC offsets and to match the first and second common mode voltages. In one embodiment, the first analog circuit is a variable gain control transimpedance amplifier (TIA) implemented using a current mode buffer, the second analog circuit is a second-order adjustable low-pass filter, whereby a three-pole adjustable low-pass filter in the compact low-power receiver is effectively produced.

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.

A unique electrical system includes a first electrical component and a second electrical component. A conductor electrically couples the first electrical component with the second electrical component. A sensor is constructed to sense an AC power flow in the conductor and output an AC signal proportional to the AC power flow. A band-pass filter is in electrical communication with the sensor and constructed to receive and filter the AC signal and to generate an AC voltage proportional on the AC signal. A controller is in electrical communication with the band-pass filter, and is operative to receive and sample the AC voltage. The controller is configured to execute program instructions to sum sequential AC voltage values received from the band-pass filter over a sample time period, and to determine whether an arc fault has occurred based on the summed AC voltage values.

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.

A programmable band-pass filter circuit, which is included by an analog front-end circuit and used for capacitance detection, includes an operational amplifier, an input resistor, a feedback resistor, and a feedback capacitor. The operational amplifier includes a first input coupled to a reference level, a second input, and an output. The input resistor has a first end coupled to a sensed capacitor and a second end coupled to the second input of the operational amplifier. The feedback resistor and feedback capacitor are connected between the second input of the operational amplifier and the output of the operational amplifier, respectively.

In some examples, a circuit includes an amplifier, a resistor, and a damping network. The amplifier has an amplifier output and first and second amplifier inputs. The first amplifier input is adapted to be coupled to a first terminal, and the second amplifier input is configured to receive a reference voltage. The resistor is coupled between the amplifier output and the first amplifier input. The damping network is coupled between the amplifier output and the first terminal.