A PAM signaling system utilizes multiple equalizers on each data lane of a serial data bus, each of the equalizers associated with a different signal eye of the serial data bus.

A continuous-time sampler has series-connected delay lines with intermediate output taps between the delay lines. Signal from an output tap can be buffered by an optional voltage buffer for performance. A corresponding controlled switch is provided with each output tap to connect the output tap to an output of the continuous-time sampler. The delay lines store a continuous-time input signal waveform within the propagation delays. Controlling the switches corresponding to the output taps with pulses that match the propagation delays can yield a same input signal value at the output. The continuous-time sampler effectively holds or provides the input signal value at the output for further processing without requiring switched-capacitor circuits that sample the input signal value onto some capacitor. In some cases, the continuous-time sampler can be a recursively-connected delay line. The continuous-time sampler can be used as the front end sampler in a variety of analog-to-digital converters.

Methods, systems, and apparatus to increase common-mode transient immunity in isolation devices is disclosed. An example apparatus includes a current mirror including an input terminal and an output terminal; a transistor including a gate terminal, a first current terminal, and a second current terminal, the gate terminal coupled to a reference voltage terminal, the first current terminal coupled to the input terminal of the current mirror, and the second current terminal coupled to an input node; a buffer including an input terminal and an output terminal, the input terminal of the buffer coupled to the output terminal of the current mirror; and a logic gate including an input terminal and an output terminal, the input terminal of the logic gate coupled to the output terminal of the buffer.

Methods, systems, and apparatus to increase common-mode transient immunity in isolation devices is disclosed. An example apparatus includes a current mirror including an input terminal and an output terminal; a transistor including a gate terminal, a first current terminal, and a second current terminal, the gate terminal coupled to a reference voltage terminal, the first current terminal coupled to the input terminal of the current mirror, and the second current terminal coupled to an input node; a buffer including an input terminal and an output terminal, the input terminal of the buffer coupled to the output terminal of the current mirror; and a logic gate including an input terminal and an output terminal, the input terminal of the logic gate coupled to the output terminal of the buffer.

An EHF receiver that determines an initial slicing voltage level and dynamically adjusts the slicing voltage level and/or amplifier gain levels to account for characteristics of the received EHF electromagnetic data signal. The architecture includes an amplifier, detector, adaptive signal slicer, and controller. The detector includes a main detector and replica detector that convert the received EHF electromagnetic data signal into a baseband signal and a reference signal. The controller uses the baseband signal and reference signal to determine an initial slicing voltage level, and dynamically adjust the slicing voltage level and the gain settings of the amplifier to compensate for changing signal conditions.

An integrated receiver supports adaptive receive equalization. An incoming bit stream is sampled using edge and data clock signals derived from a reference clock signal. A phase detector determines whether the edge and data clock signals are in phase with the incoming data, while some clock recovery circuitry adjusts the edge and data clock signals as required to match their phases to the incoming data. The receiver employs the edge and data samples used to recover the edge and data clock signals to note the locations of zero crossings for one or more selected data patterns. The pattern or patterns may be selected from among those apt to produce the greatest timing error. Equalization settings may then be adjusted to align the zero crossings of the selected data patterns with the recovered edge clock signal.

A system and method for encoding multi-bit features into sinusoidal waveforms at selected phase angles. The method includes receiving input digital data and encoding the input digital data in a sinusoidal waveform by modulating the sinusoidal waveform at selected phase angles within a period of the sinusoidal waveform, thereby creating a modulated sinusoidal waveform. An encoded analog waveform is generated, using a digital-to-analog converter, from a digital representation of the modulated sinusoidal waveform. The modulating includes forming a first data notch at a first phase angle of the selected phase angles wherein the first data notch includes a first plurality of transition features and subtends a first phase angle range about the first phase angle, the first plurality of transition features being representative of a first plurality of bit values included within the input digital data.

An equalizer that has a wide variable gain range and that can implement equalization for a communication medium such as on-board wiring or a cable having various wiring lengths. The equalizer includes a core circuit and a source follower connected to a subsequent stage of the core circuit. The core circuit includes a differential pair including a first transistor and a second transistor, and a zero point generation circuit connected between a second terminal of the first transistor and a second terminal of the second transistor. The source follower includes a third transistor and a fourth transistor, a variable bias current source is connected to the third and fourth transistors, and a load in which a capacitive element and a resistor element are connected in series via a switching element is connected to wiring that connects the third and fourth transistors to an output terminal.

An occurrence of a first set of n periods of a frequency-shift-keying (FSK)-modulated waveform is counted, where n is an integer number. The n periods of the FSK-modulated waveform in the first set have a first time duration. An occurrence of a second set of n periods of the waveform is counted. The n periods of the waveform in the second set have a second time duration. The first time duration is determined based on the counting of the first set of n periods. The second time duration is determined based on the counting of the second set of n periods. A difference between the first time duration and the second time duration is compared to a threshold. Changes in frequency of the waveform are detected based on the comparing of the difference between the first time duration and the second time duration to the threshold.

A multi-carrier data communications system and method having high spectral efficiency. The method includes encoding input digital data at selected phase angles of a plurality of sinusoidal waveforms to create a plurality of modulated sinusoidal waveforms. An output analog waveform is generated where the output analog waveform includes a plurality of encoded analog communication signals corresponding to a plurality of digital representations of the plurality of modulated sinusoidal waveforms. The encoding is performed so that adjacent ones of the plurality of modulated sinusoidal waveforms are separated in frequency by less than 15 Hz and any sideband included within the output analog waveform is of a power at least 50 dB below a power of the encoded analog communication signal associated with the sideband.