Amplifier circuitry has sampling circuitry which samples an input voltage, a quantizer which quantizes an output voltage of the sampling circuitry and outputs an output code, a differential amplifier which amplifies a differential voltage between the output voltage of the sampling circuitry and a reference voltage and performs offset adjustment according to the output code of the quantizer, and a first capacitor which is connected between an output node of the differential amplifier and an output node of the sampling circuitry.

A programmable gain amplifier may include: (a) a differential amplifier having first and second input terminals and first and second output terminals, the differential amplifier providing an output signal of the programmable gain amplifier across the first and second output terminals of the differential amplifier; (b) a first set of one or more resistors coupling the first output terminal of the differential amplifier to the first input terminal of the differential amplifier; (c) a second set of one or more resistors coupling the first input terminal of the differential amplifier to a first input terminal of the programmable gain amplifier; and (d) a first set of one or more switches each connected in parallel with one or more resistors in the first or second set of resistors. The first set of switches may include two or more individually programmable switches. Each of the switches may be implemented by an input-signal independent switch disclosed herein.

Disclosed is a reconfigurable amplifier and an amplification method thereof, the amplifier includes an input selector, a first amplifying circuit, and a second amplifying circuit. The input selector is configured to select one of a voltage input and a current input based on a voltage measurement mode and a current measurement mode. The first amplifying circuit includes a first load element, and is configured to apply a voltage corresponding to the voltage input to the first load element in the voltage measurement mode and receive the current input in the current measurement mode and block a current flowing through the first load element. The second amplifying circuit is configured to mirror a current flowing through the first amplifying circuit in response to one of the voltage input and the current input and generate an output voltage based on the mirrored current.

In accordance with embodiments of the present disclosure, a method for power supply rejection for an amplifier may include generating a correction signal by multiplying a quantity indicative of a power supply voltage of the amplifier by a transfer function defining a response from the power supply voltage of the amplifier to an output signal of the amplifier and subtracting the correction signal from a signal within a signal path of a circuit comprising the amplifier.

An amplifier circuit having improved common mode rejection is provided. This can be achieved by estimating the common mode value of an input signal and using this to adjust a target common mode voltage at the output of the amplifier. This can help avoid the differential gain becoming modified by the common mode voltage.

A CMOS channel select filter for DVB-H direct-conversion receives based on a transresistance amplifier (TRA) is disclosed. The channel select filter includes a fully differential transresistance amplifier (FDTRA) configured to change an input current at each differential input terminal to a voltage at each differential output terminal based on an impedance at a corresponding differential impedance terminal. The channel select filter also includes two feedback resistors, each having one end connected to a respective differential output terminal of the FDTRA and having another end connected to the node, two first capacitors, each connected between ground and the node, and two second capacitors, each connected between ground and a respective differential impedance terminal.

In accordance with embodiments of the present disclosure, a method for power supply rejection for an amplifier may include generating a correction signal by multiplying a quantity indicative of a power supply voltage of the amplifier by a transfer function defining a response from the power supply voltage of the amplifier to an output signal of the amplifier and subtracting the correction signal from a signal within a signal path of a circuit comprising the amplifier.

An amplifier that amplifies a differential signal includes first and second input terminals for receiving two input signals; first and second diodes each including anode and cathode, the anodes being electrically connected to the first and second input terminals; first and second bias current sources being respectively electrically connected to the cathodes of the first and second diodes; an operational amplifier connected to the cathode of the first diode and the cathode of the second diode and configured to amplify a differential signal between signals generated at the cathodes of the first and second diodes; a capacitive element being electrically connected between an input and an output of the operational amplifier; and a differential amplifier provided between the operational amplifier and the first and second input terminals and configured to amplify the two input signals. The first and second bias current sources include a current mirror circuit.

An amplifier circuit includes: an amplifier; and a bias circuit that controls an operation point of the amplifier. The amplifier includes: a load resistor; a differential transistor pair electrically coupled to the load resistor; and a tail transistor electrically coupled to the differential transistor pair. The bias circuit includes: a voltage generator circuit that generates a reference voltage corresponding to a sum of a threshold voltage of a transistor in the differential transistor pair and a saturation drain voltage of the tail transistor; and a current generator circuit that generates a reference current that is proportional to a difference between a power supply voltage of the amplifier circuit and the reference voltage by using a reference resistor. The current generator circuit is electrically coupled to the amplifier such that a tail current that flows through the tail transistor is proportional to the reference current.

Methods and systems are described for receiving, at an input differential branch pair, a set of input signals, and responsively generating a first differential current, receiving, at an input of an offset voltage branch pair, an offset voltage control signal, and responsively generating a second differential current, supplementing a high-frequency component of the second differential current by injecting a high-pass filtered version of the set of input signals into the input of the offset voltage branch pair using a high-pass filter, and generating an output differential current based on the first and second differential currents using an amplifier stage connected to the input differential branch pair and the offset voltage branch pair.