Systems and methods that integrate a directional coupling function with directivity that does not have output loss are disclosed. For example, a power amplifier circuit arrangement includes an input terminal to receive an input signal; amplifier circuitry including a first amplifier stage, a second amplifier stage, and a virtual ground node, where an input of the first amplifier stage is coupled to the input terminal, an output of the first amplifier stage is coupled to an input of the second amplifier stage via the virtual ground node, and an output of the second amplifier stage is coupled to the input of the first amplifier stage via feedback circuitry; an output terminal coupled to the output of the second amplifier stage, the output terminal to output an amplified signal; and a directional coupler terminal coupled to the virtual ground node.

Certain aspects of the present disclosure provide methods and apparatus for implementing an amplification system. The amplification system includes an amplifier comprising differential inputs and an output. The differential inputs include an inverting input and a non-inverting input. The amplification system further includes a feedback path from the output coupled to the inverting input. The feedback path from the output is coupled to at least one of an inverting amplifier or buffer, and the at least one of the inverting amplifier or buffer is further coupled to the non-inverting input.

A differential amplifier which does not have an effect of noise resistance deterioration, waveform distortion, and a lower bandwidth while having a wide input range is realized. The differential amplifier does not cause deterioration in a signal quality due to an increase in an input load, and it is not necessary to additionally provide a configuration for generating a reference voltage. The differential amplifier includes a differential amplification circuit and an output circuit for amplifying and outputting a differential output from the differential amplification circuit. The differential amplification circuit includes a first conductive type first differential pair which supplies output currents according to a positive phase input signal and a reverse phase input signal to the output circuit, a second conductive type second differential pair which supplies output currents according to a positive phase input signal and a reverse phase input signal to the output circuit, a detector which detects an operation state of a differential pair, and an alternative current supplying circuit which supplies an alternative current for the output current of the differential pair which has been turned off to the output circuit.

Power consumption of a signal processing circuit is reduced. Further, power consumption of a semiconductor device including the signal processing circuit is reduced. The signal processing circuit includes a reference voltage generation circuit, a voltage divider circuit, an operational amplifier, a bias circuit for supplying bias current to the operational amplifier, and first and second holding circuits. The first holding circuit is connected between the reference voltage generation circuit and the bias circuit. The second holding circuit is connected between the voltage divider circuit and a non-inverting input terminal of the operational amplifier. Reference voltage from the reference voltage generation circuit and reference voltage from the voltage divider circuit can be held in the first and second holding circuits, respectively, so that the reference voltage generation circuit can stop operating. Thus, power consumption of the reference voltage generation circuit can be reduced.

A low noise amplifier (LNA) includes a pair of n-type transistors, each configured to provide a first transconductance; a pair of p-type transistors, each configured to provide a second transconductance; a first pair of coupling capacitors, cross-coupled between the pair of n-type transistors, and configured to provide a first boosting coefficient to the first transconductance; and a second pair of coupling capacitors, cross-coupled between the pair of p-type transistors, and configured to provide a second boosting coefficient to the second transconductance, wherein the LNA is configured to use a boosted effective transconductance based on the first and second boosting coefficients, and the first and second transconductances to amplify an input signal.

A transimpedance amplifier (TIA) structure includes an input node with a variable inductance component serving to reduce variation in peak amplitude over different gain conditions. According to certain embodiments, an inductor at the TIA input has a first node in communication with a Field Effect Transistor (FET) drain, and a second node in communication with the FET source. A control voltage applied to the FET gate effectively controls the input inductance by adding a variable impedance across the inductor. Under low gain conditions, lowering of inductance afforded by the control voltage applied to the FET reduces voltage peaking. TIAs in accordance with embodiments may be particularly suited to operate over a wide dynamic range to amplify incoming electrical signals received from a photodiode.

A data output device is provided. The data output device includes a converter circuit configured to generate a conversion signal based on an output signal; a boosting circuit configured to generate a boosting signal based on the output signal; and an output circuit configured to generate the output signal based on an input signal and a feedback signal, the feedback signal being based on the conversion signal and the boosting signal.

A Second-Generation Current Conveyor (CCII) has a three-port network with ports designated as X, Y, and Z, wherein the CCII includes a tunable feedback network. The tunable feedback network may be provided between at least two of the ports, e.g., ports Z and Y. The tunable feedback network may comprise a tunable RC (Resister-Capacitor) network which may be provided by solid-state components such as a MOS (Metal-Oxide Semiconductor) device or a MOS resistor (for the resistive element) and a varactor (for the capacitive element).

A negative feedback inductor and a gate inductor are formed in different wiring layers of a substrate so as to be at least partially overlapped with each other in a plan view. When the lower wiring layer is thinner and the upper wiring layer is thicker, the negative feedback inductor Lc is formed in the lower wiring layer that is thinner.

An amplifier includes a first capacitor connected between an input node and a floating node, a second capacitor connected between the floating node and an output node, an amplifying element connected between a power supply voltage and the output node and operating in response to a voltage level of the floating node, a current bias source connected between the output node and a ground voltage, a first reset switch connected between the floating node and an intermediate node and operating in response to a reset bias, a second reset switch connected between the intermediate node and the output node and operating in response to the reset bias, and a reset bias generator circuit that outputs the reset bias in response to a reset signal. The reset bias is one of a reset voltage of the intermediate node, the power supply voltage, and the ground voltage.