A device, a memory interface device, and a method of implementing an active inductor circuit are disclosed. In one aspect, the device includes one or more active inductor circuits, each including a first metal-oxide-semiconductor (MOS) transistor and a second MOS transistor. The first MOS transistor has a first terminal connected to a first voltage level, a second terminal connected to a resistor, and a gate terminal. The second MOS transistor has a first terminal connected to the first voltage level, a second terminal connected to a first current source and the gate terminal of the first MOS transistor, and a gate terminal connected to the resistor and to a capacitor connected to a second voltage level. One of the first MOS transistor and the second MOS transistor is a p-channel MOS (PMOS) transistor, and another of the first MOS transistor and the second MOS transistor is an n-channel MOS (NMOS) transistor.

Universal Serial Bus (USB) repeater circuits and methods of operating the same for communicating data signals from a first pair of data terminals to a second pair of data terminals of the repeater. In a first channel, an amplifier stage in a receiver amplifies a differential signal received at the first pair of data terminals to generate a differential signal at first and second output nodes of the receiver, and a transmitting circuit transmits a differential signal at the second pair of data terminals responsive to the differential signal at the first and second output nodes of the receiver. The receiver includes a hysteresis stage that receives an offset in opposition to the differential signal at the first and second output nodes of the receiver. End-of-packet (EOP) dribble in USB communications in the HS mode is reduced by the offset at the hysteresis stage.

An N-tap feedforward equalizer (FFE) comprises a set of N FFE taps coupled together in parallel, a filter coupled between the (N−1)th FFE tap and the Nth FFE tap, and a summer coupled to an output of the set of N FFE taps. Each FFE tap includes a unique sample-an-hold (S/H) circuit that generates a unique time-delayed signal and a unique transconductance stage that generates a unique transconductance output based on the unique time-delayed signal. The filter causes the N-tap FFE to have the behavior of greater than N taps. In some examples, the filter is a first order high pass filter that causes coefficients greater than N to have an opposite polarity of the Nth coefficient. In some examples, the filter is a first order low pass filter that causes coefficients greater than N to have the same polarity as the Nth coefficient.

A circuit is disclosed, in accordance with some embodiments. The circuit includes a transistor stage, a resistive element, a first tunable capacitive element and a second tunable capacitive element. The transistor stage includes a first input/output terminal and a second input/output terminal. The resistive element is connected to the transistor stage. The first tunable capacitive element is connected in parallel with the resistive element. The second tunable capacitive element is connected to the second input/output terminal of the transistor stage.

The detection matrix for an Orthogonal Differential Vector Signaling code is typically embodied as a transistor circuit with multiple active signal inputs. An alternative detection matrix approach uses passive resistor networks to sum at least some of the input terms before active detection.

A circuit is disclosed, in accordance with some embodiments. The circuit includes a transistor stage, a resistive element, a first tunable capacitive element and a second tunable capacitive element. The transistor stage includes a first input/output terminal and a second input/output terminal. The resistive element is connected to the transistor stage. The first tunable capacitive element is connected in parallel with the resistive element. The second tunable capacitive element is connected to the second input/output terminal of the transistor stage. The first tunable capacitive element and the second tunable capacitive element are configured to be selectively turned on and off to provide different frequency responses.

Provided herein are apparatus and methods for a multi-stage signal-processing circuit. The signal-processing circuit can include multiple configurable stages that can be cascaded and configured to process an input signal. Control circuitry can be used to select an output of the configurable stages. Serial data can be recovered with good signal integrity using a signal monitor with the configurable stages by virtually placing the signal monitor on a buffered output node.

A programmable equalizer and related method are provided. The equalizer includes a pair of current-setting field effect transistors (FETs) coupled in series with a pair of input FETs and a pair of load resistors, respectively, between a first voltage rail (Vdd) and a second voltage rail (ground). A programmable equalization circuit is coupled between the sources of the input FETs, comprising a plurality of selectable resistive paths and a variable capacitor, which could also be configured as a plurality of selectable capacitive paths. Each of the selectable resistive paths (as well as each of the selectable capacitive paths) include a selection FET for selectively coupling the corresponding resistive (or capacitive) path between the sources of the input FETs. In the case where one of the input FETs is biased with a reference gate voltage, the source of each selection FET is coupled to the source of such input FET.

An N-tap feedforward equalizer (FFE) comprises a set of N FFE taps coupled together in parallel, a filter coupled between the (N−1)th FFE tap and the Nth FFE tap, and a summer coupled to an output of the set of N FFE taps. Each FFE tap includes a unique sample-an-hold (S/H) circuit that generates a unique time-delayed signal and a unique transconductance stage that generates a unique transconductance output based on the unique time-delayed signal. The filter causes the N-tap FFE to have the behavior of greater than N taps. In some examples, the filter is a first order high pass filter that causes coefficients greater than N to have an opposite polarity of the Nth coefficient. In some examples, the filter is a first order low pass filter that causes coefficients greater than N to have the same polarity as the Nth coefficient.

A circuit is disclosed, in accordance with some embodiments. The circuit includes a transistor stage, a resistive element, a first tunable capacitive element and a second tunable capacitive element. The transistor stage includes a first input/output terminal and a second input/output terminal. The resistive element is connected to the transistor stage. The first tunable capacitive element is connected in parallel with the resistive element. The second tunable capacitive element is connected to the second input/output terminal of the transistor stage.