A four-phase (or multi-phase) generation circuit, related method of operation, and transceivers or other systems utilizing such a circuit, are disclosed herein. In one example embodiment, the circuit includes two input ports respectively configured to receive positive and negative differential input signals, and four output ports respectively configured to output first, second, third and fourth output signals, respectively, the second, third, and fourth output signals being respectively phase-shifted relative to the first output signal by or substantially by 90, 180, and 270 degrees. Also, the circuit includes four SR latches respectively including output terminals that are respectively coupled to the respective output ports. Further, the circuit includes two tunable delay circuits respectively coupled at least indirectly between the input ports and latches, and two comparison circuits configured to output respective feedback signals. The latches receive two delayed input signals provided by the delay circuits based upon the feedback signals.

A four-phase (or multi-phase) generation circuit, related method of operation, and transceivers or other systems utilizing such a circuit, are disclosed herein. In one example embodiment, the circuit includes two input ports respectively configured to receive positive and negative differential input signals, and four output ports respectively configured to output first, second, third and fourth output signals, respectively, the second, third, and fourth output signals being respectively phase-shifted relative to the first output signal by or substantially by 90, 180, and 270 degrees. Also, the circuit includes four SR latches respectively including output terminals that are respectively coupled to the respective output ports. Further, the circuit includes two tunable delay circuits respectively coupled at least indirectly between the input ports and latches, and two comparison circuits configured to output respective feedback signals. The latches receive two delayed input signals provided by the delay circuits based upon the feedback signals.

An integrated circuit can comprise an output terminal, a power transistor having a first current electrode coupled to the output terminal and a second current electrode coupled to a power supply terminal, a driver having an output coupled to a control electrode of the power switch, a capacitor having a first terminal coupled to the output terminal and a second terminal coupled to a circuit node, a first low pass filter coupled between the circuit node and an input of the driver, the first low pass filter having a first cut off frequency, a set of current sources, and a second low pass filter coupled between the circuit node and an output of the set of current sources. The second low pass filter can have a second cut off frequency that is higher than the first cut off frequency.

An integrated circuit can comprise an output terminal, a power transistor having a first current electrode coupled to the output terminal and a second current electrode coupled to a power supply terminal, a driver having an output coupled to a control electrode of the power switch, a capacitor having a first terminal coupled to the output terminal and a second terminal coupled to a circuit node, a first low pass filter coupled between the circuit node and an input of the driver, the first low pass filter having a first cut off frequency, a set of current sources, and a second low pass filter coupled between the circuit node and an output of the set of current sources. The second low pass filter can have a second cut off frequency that is higher than the first cut off frequency.

An apparatus and method for a frequency based integrated circuit that selectively filters out unwanted bands or regions of interfering frequencies utilizing one or more tunable notch or bandpass filters or tunable low or high pass filters capable of operating across multiple frequencies and multiple bands in noisy RF environments. The tunable filters are fabricated within the same integrated circuit package as the associated frequency based circuitry, thus minimizing R, L, and C parasitic values, and also allowing residual and other parasitic impedance in the associated circuitry and IC package to be absorbed and compensated.

An apparatus and method for a frequency based integrated circuit that selectively filters out unwanted bands or regions of interfering frequencies utilizing one or more tunable notch or bandpass filters or tunable low or high pass filters capable of operating across multiple frequencies and multiple bands in noisy RF environments. The tunable filters are fabricated within the same integrated circuit package as the associated frequency based circuitry, thus minimizing R, L, and C parasitic values, and also allowing residual and other parasitic impedance in the associated circuitry and IC package to be absorbed and compensated.

A method of constructing an RF filter comprises designing an RF filter that includes a plurality of resonant elements disposed, a plurality of non-resonant elements coupling the resonant elements together to form a stop band having a plurality of transmission zeroes corresponding to respective frequencies of the resonant elements, and a sub-band between the transmission zeroes. The non-resonant elements comprise a variable non-resonant element for selectively introducing a reflection zero within the stop band to create a pass band in the sub-band. The method further comprises changing the order in which the resonant elements are disposed along the signal transmission path to create a plurality of filter solutions, computing a performance parameter for each of the filter solutions, comparing the performance parameters to each other, selecting one of the filter solutions based on the comparison of the computed performance parameters, and constructing the RF filter using the selected filter solution.

A method of constructing an RF filter comprises designing an RF filter that includes a plurality of resonant elements disposed, a plurality of non-resonant elements coupling the resonant elements together to form a stop band having a plurality of transmission zeroes corresponding to respective frequencies of the resonant elements, and a sub-band between the transmission zeroes. The non-resonant elements comprise a variable non-resonant element for selectively introducing a reflection zero within the stop band to create a pass band in the sub-band. The method further comprises changing the order in which the resonant elements are disposed along the signal transmission path to create a plurality of filter solutions, computing a performance parameter for each of the filter solutions, comparing the performance parameters to each other, selecting one of the filter solutions based on the comparison of the computed performance parameters, and constructing the RF filter using the selected filter solution.

An apparatus for filtering an electrical power signal in an Ethernet communication system includes a link interface, a power interface, and a filter connected between the link interface and the power interface. The link interface is configured to connect to an Ethernet link. The power interface is configured to connect to one or both of (i) a power-supply that supplies the electrical power signal for transfer over the Ethernet link, and (ii) a circuit that consumes the electrical power signal transferred over the Ethernet link. The filter includes at least (i) a primary inductor configured to filter the electrical power signal transferred to or from the Ethernet link, and (ii) one or more complementary inductors connected in series with the primary inductor, the one or more complementary inductors configured to reduce a parasitic capacitance of the filter.

An apparatus for filtering an electrical power signal in an Ethernet communication system includes a link interface, a power interface, and a filter connected between the link interface and the power interface. The link interface is configured to connect to an Ethernet link. The power interface is configured to connect to one or both of (i) a power-supply that supplies the electrical power signal for transfer over the Ethernet link, and (ii) a circuit that consumes the electrical power signal transferred over the Ethernet link. The filter includes at least (i) a primary inductor configured to filter the electrical power signal transferred to or from the Ethernet link, and (ii) one or more complementary inductors connected in series with the primary inductor, the one or more complementary inductors configured to reduce a parasitic capacitance of the filter.