A system for sensing an electrical quantity may include a sensing stage configured to sense the electrical quantity and generate a sense signal indicative of the electrical quantity, wherein the electrical quantity is indicative of an electrical signal generated by a Class-DG amplifier configured to drive a load wherein the Class-DG amplifier has multiple signal-level common modes and a common-mode compensator configured to compensate for changes to a common-mode voltage of a differential supply voltage of the driver occurring when switching between signal-level common modes of the Class-DG amplifier.

An asymmetric signal path approach is used to extract differential signals out of the photodetector (e.g., a photodiode) for amplification by a differential transimpedance amplifier (TIA). This asymmetric-path differential TIA configuration has less low-frequency Inter Symbol Interference (ISI) (also known as Baseline Wander), less high-frequency noise amplification, and higher bandwidth capabilities. There is no power penalty with this design in comparison to a single-ended TIA, can extend the range of the link for a given system power consumption, and can decrease transmitter power for a given range.

A sample-and-hold amplifier can include: an operational amplifier; a sampling capacitor having a first terminal coupled to an inverting input terminal of the operational amplifier, and a second terminal coupled to a reference ground; and a switching circuit configured to switch feedback paths of the sample-and-hold amplifier in a first stage and a second stage, such that an offset voltage of the operational amplifier is at least partially eliminated.

A transimpedance amplifier is provided for converting a current between its two input terminals to a voltage over its two output terminals comprising a high-speed level shifter configured for creating a difference in input DC voltage and for being transparent for alternating voltages, an input biasing network configured for reverse biasing a photodiode connected to at least one of the input terminals and transparent for a feedback signal from the feedback network which is differentially and DC-coupled with the output terminals of the voltage amplifier and outputs of the feedback network are differentially and DC-coupled with the input biasing network of which outputs are coupled with inputs of the level shifter which is differentially and DC-coupled with input terminals of the voltage amplifier.

An analog front-end receiver including a termination resistor configured to receive first and second differential signals from different data lines, the second differential signal being differential with respect to the first differential signal, an active equalizer configured to receive a first input differential signal through a first input node and a second input differential signal through a second input node, the first and second input differential signals both having an input common mode voltage, the first and second input differential signals being based on the first and second differential signal, respectively, and output first and output differential signals to first and second output nodes, respectfully, the second output differential signal being differential with respect to the first output differential signal, and an input common mode voltage generator configured to adjust the input common mode voltage to be equal to an output common mode voltage of the first output differential signal.

The present application discloses an amplifier and a method for controlling a common mode voltage thereof. The method includes: generating a control signal according to a positive-terminal input signal, a negative-terminal input signal and a target common mode voltage; and coupling the controlling signal to a first terminal of a positive-terminal capacitor and a first terminal of a negative-terminal capacitor, to adjust degree of conduction of a positive-terminal p-type transistor and degree of conduction of a negative-terminal p-type transistor, or to adjust degree of conduction of a positive-terminal n-type transistor and degree of conduction of a negative-terminal n-type transistor, thereby changing a common mode voltage.

A differential residue amplifier fits between Analog-to-Digital Converter (ADC) stages. Switched-Capacitor Common-Mode Feedback circuits determine voltage shifts. An AC-coupled input network uses switched capacitors to shift upward voltages of the differential inputs to the residue amplifier to apply to an upper pair of p-channel differential transistors with sources connected to the power supply. The AC-coupled input network also shifts downward in voltage the differential inputs to the residue amplifier to apply to a lower pair of n-channel differential transistors with grounded sources. The drains of the p-channel differential transistors connect to differential outputs through p-channel cascode transistors. N-channel cascode transistors connect the drains of the n-channel differential transistors to the differential outputs. The drains of differential transistors can be input to differential amplifiers to drive the gates of the cascode transistors for gain boosting. No tail current is used, allowing for wider output-voltage swings with low supply voltages.

An asymmetric signal path approach is used to extract differential signals out of the photodetector (e.g., a photodiode) for amplification by a differential transimpedance amplifier (TIA). This asymmetric-path differential TIA configuration has less low-frequency Inter Symbol Interference (ISI) (also known as Baseline Wander), less high-frequency noise amplification, and higher bandwidth capabilities. There is no power penalty with this design in comparison to a single-ended TIA, can extend the range of the link for a given system power consumption, and can decrease transmitter power for a given range.

A system for sensing an electrical quantity may include a sensing stage configured to sense the electrical quantity and generate a sense signal indicative of the electrical quantity, wherein the electrical quantity is indicative of an electrical signal generated by a Class-DG amplifier configured to drive a load wherein the Class-DG amplifier has multiple signal-level common modes and a common-mode compensator configured to compensate for changes to a common-mode voltage of a differential supply voltage of the driver occurring when switching between signal-level common modes of the Class-DG amplifier.

An analog front-end receiver including a termination resistor configured to receive first and second differential signals from different data lines, the second differential signal being differential with respect to the first differential signal, an active equalizer configured to receive a first input differential signal through a first input node and a second input differential signal through a second input node, the first and second input differential signals both having an input common mode voltage, the first and second input differential signals being based on the first and second differential signal, respectively, and output first and output differential signals to first and second output nodes, respectfully, the second output differential signal being differential with respect to the first output differential signal, and an input common mode voltage generator configured to adjust the input common mode voltage to be equal to an output common mode voltage of the first output differential signal.