A low voltage drive circuit (LVDC) includes a digital to digital converter that converts transmit digital data into a digital input signal, wherein the transmit digital data is synchronized to a clock rate of a host device and the digital input signal is synchronized to a clock rate of a bus to which the LVDC is coupled. An output limited digital to analog is converter converts the digital input signal into analog outbound data by generating a DC component and converting the digital input signal into an oscillating component at a first frequency, wherein magnitude of the oscillating component is limited to a range that is less than a difference between magnitudes of power supply rails of the LVDS, and wherein the oscillating component and the DC component are combined to produce the analog outbound data. A drive sense circuit conveys the analog outbound data as variances in loading of the bus at the first frequency and wherein analog inbound data is represented within an analog receive signal as variances in loading of the bus at a second frequency.

A signal transmission device includes a communication unit that performs communication using differential transmission with an electronic device via a differential wiring, and a signal processing unit that performs signal processing related to the communication, in which the communication unit is capable of receiving, via the differential wiring, communication signals transmitted from the electronic device at each of a plurality of signal transmission rates including at least a first signal transmission rate and a second signal transmission rate lower than the first signal transmission rate, the communication unit measures an amplitude of the communication signals received from the electronic device at the second signal transmission rate, and the signal processing unit detects a short-circuit failure of a filter circuit on the basis of the amplitude measured by the communication unit.

A high-speed signaling system with adaptive transmit pre-emphasis. A transmit circuit has a plurality of output drivers to output a first signal onto a signal path. A receive circuit is coupled to receive the first signal via the signal path and configured to generate an indication of whether the first signal exceeds a threshold level. A first threshold control circuit is coupled to receive the indication from the receive circuit and configured to adjust the threshold level according to whether the first signal exceeds the threshold level. A drive strength control circuit is coupled to receive the indication from the receive circuit and configured to adjust a drive strength of at least one output driver of the plurality of output drivers according to whether the first signal exceeds the threshold level.

A hybrid voltage mode (VM) and current mode (CM) four-level pulse amplitude modulation (PAM-4) transmitter circuits (a.k.a. drivers) is calibrated using a configurable replica circuit and calibration control circuitry. The replica circuit includes an on-chip termination impedance to mimic a receiver's termination impedance. The amount of level enhancement provided by the current mode circuitry is calibrated by adjusting the current provided to the output node and sunk from the output node by the replica current mode circuitry while the replica voltage mode circuitry is driving an intermediate PAM-4 level. After the level enhancement has been set, the non-linearity between levels is calibrated by adjusting the amount of current provided to the output node by the replica current mode circuitry while the replica voltage mode circuitry is driving a maximum output voltage level.

A low voltage drive circuit includes a transmit digital to analog circuit that converts transmit digital data into analog outbound data by: generating a DC component; a first plurality of oscillations, wherein each oscillation of the first plurality of oscillations has first unique oscillation characteristics; selecting one of the first plurality of oscillations in accordance with a first portion of the transmit digital data to produce a first selected oscillation; generating a second plurality of oscillations, wherein each oscillation of the second plurality of oscillations has second unique oscillation characteristics; selecting one of the second plurality of oscillations in accordance with a second portion of the transmit digital data to produce a second selected oscillation, and outputting the first selected oscillation and the second selected oscillation on an n-bit-by-n-bit basis to produce an oscillating component, wherein the DC component is combined with the oscillating component to produce the analog outbound data. A drive sense circuit drives an analog transmit signal onto a bus, wherein the analog outbound data is represented within the analog transmit signal as variances in loading of the bus in a first frequency range and wherein analog inbound data is represented within an analog receive signal as variances in loading of the bus in a second frequency range.

A low voltage drive circuit includes a transmit digital to analog circuit that converts transmit digital data into analog outbound data by: generating a DC component; generating a first oscillation at a first frequency; generating a second oscillation at the first frequency; and outputting the first oscillation or the second oscillation on a bit-by-bit basis in accordance with the transmit digital data to produce an oscillating component, wherein the DC component is combined with the oscillating component to produce the analog outbound data, and wherein the oscillating component and the DC component are combined to produce the analog outbound data. A drive sense circuit drives an analog transmit signal onto a bus, wherein the analog outbound data is represented within the analog transmit signal as variances in loading of the bus at the first frequency and wherein analog inbound data is represented within an analog receive signal as variances in loading of the bus at a second frequency.

A low voltage drive circuit (LVDC) includes a digital to digital converter that converts transmit digital data into a digital input signal, wherein the transmit digital data is synchronized to a clock rate of a host device and the digital input signal is synchronized to a clock rate of a bus to which the LVDC is coupled. An output limited digital to analog is converter converts the digital input signal into analog outbound data by generating a DC component and converting the digital input signal into an oscillating component at a first frequency, wherein magnitude of the oscillating component is limited to a range that is less than a difference between magnitudes of power supply rails of the LVDS, and wherein the oscillating component and the DC component are combined to produce the analog outbound data. A drive sense circuit conveys the analog outbound data as variances in loading of the bus at the first frequency and wherein analog inbound data is represented within an analog receive signal as variances in loading of the bus at a second frequency.

An apparatus is described. The apparatus includes a decision feedback equalizer circuit having a summation circuit. The summation circuit has a differential pair that includes first and second transistors coupled to a current source. The current source is to draw a current through the first and second transistors. The decision feedback circuit also includes a circuit to adjust the current to compensate for a change in electron mobility of at least one transistor of the current source.

A low voltage drive circuit includes a transmit digital to analog circuit that converts transmit digital data into analog outbound data by: generating a DC component; a first plurality of oscillations, wherein each oscillation of the first plurality of oscillations has first unique oscillation characteristics; selecting one of the first plurality of oscillations in accordance with a first portion of the transmit digital data to produce a first selected oscillation; generating a second plurality of oscillations, wherein each oscillation of the second plurality of oscillations has second unique oscillation characteristics; selecting one of the second plurality of oscillations in accordance with a second portion of the transmit digital data to produce a second selected oscillation, and outputting the first selected oscillation and the second selected oscillation on an n-bit-by-n-bit basis to produce an oscillating component, wherein the DC component is combined with the oscillating component to produce the analog outbound data. A drive sense circuit drives an analog transmit signal onto a bus, wherein the analog outbound data is represented within the analog transmit signal as variances in loading of the bus in a first frequency range and wherein analog inbound data is represented within an analog receive signal as variances in loading of the bus in a second frequency range.

A low voltage drive circuit includes a transmit digital to analog circuit that converts transmit digital data into analog outbound data by: generating a DC component; generating a first oscillation at a first frequency; generating a second oscillation at the first frequency; and outputting the first oscillation or the second oscillation on a bit-by-bit basis in accordance with the transmit digital data to produce an oscillating component, wherein the DC component is combined with the oscillating component to produce the analog outbound data, and wherein the oscillating component and the DC component are combined to produce the analog outbound data. A drive sense circuit drives an analog transmit signal onto a bus, wherein the analog outbound data is represented within the analog transmit signal as variances in loading of the bus in a first frequency range and wherein analog inbound data is represented within an analog receive signal as variances in loading of the bus in a second frequency range.