Disclosed herein are transconductance circuits, as well as related methods and devices. In some embodiments, a transconductance circuit may include an amplifier having a first input coupled to a voltage input of the transconductance circuit, and a switch coupled between an output of the amplifier and a second input of the amplifier.

A differential switched capacitor neural amplifier comprises a sampling stage (SMP) with a plurality of differential inputs for receiving a plurality of input voltages and with at least one pair of digitally adjustable charge stores for sampling the plurality of input voltages, a summation stage (SM) for summing up charges resulting from the sampled plurality of input voltages in order to generate a summation signal, the summation stage (SM) being connected downstream to the sampling stage (SMP), and a buffer and activation stage (ACB) that is configured to apply an activation function and to generate a buffered output voltage at a differential output, based on the summation signal.

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.

Methods, systems, and devices for varying a time average for feedback of a memory system are described. An apparatus may include a voltage supply, a memory array, and a regulator coupled with the voltage supply and memory array and configured to supply a first voltage received from the voltage supply to the memory array. The apparatus may also include a voltage sensor configured to measure a second voltage of the memory array and a digital feedback circuit coupled with the memory array and regulator and configured to generate feedback comprising information averaged over a duration based at least in part on the second voltage measured by the voltage sensor and to transmit an analog signal to the regulator based at least in part on the feedback.

One example includes a differential amplifier, a voltage weighting element, coupled to a voltage source which provides an input voltage, to provide a reference voltage with a constant power limit when the input voltage varies, an error amplifier configured to receive and compare the reference voltage provided from the voltage weighting element and a feedback sensed voltage provided from the differential amplifier to identify whether the sensed voltage exceeds the reference voltage, and a pulse width modulation (PWM) controller, coupled to a power transformer and the error amplifier, that reduces a transformer input current provided to the power transformer based on the comparison of the reference voltage from the voltage weighting element and the feedback sensed voltage from the differential amplifier.

Low-noise optical differential receivers are described. Such differential receivers may include a differential amplifier having first and second inputs and first and second outputs, and four photodetectors. A first and a second of such photodetectors are coupled to the first input of the differential amplifier, and a third and a fourth of such photodetectors are coupled to the second input of the differential amplifier. The anode of the first photodetector and the cathode of the second photodetector are coupled to the first input of the differential amplifier. The cathode of the third photodetector and the anode of the fourth photodetector are coupled to the second input of the differential amplifier. The optical receiver may involve two stages of signal subtraction, which may significantly increase noise immunity.

An amplifier stage uses a loaded transistor amplifier circuit including a load that causes greater second order harmonic distortion energy than third order harmonic distortion energy to be produced in said loaded transistor amplifier circuit for amplifying a source audio signal to produce an audio output signal. The spectrum of the fundamental orders of harmonic distortion is adjusted to improve perceived sound quality or listening enjoyment.

An amplifier includes a first input transistor, a second input transistor, a first cascode transistor, a second cascode transistor, a first current mirror circuit, and a second current mirror circuit. The first input transistor is coupled to a first input terminal. The second input transistor is coupled to a second input terminal and the first input transistor. The first cascode transistor is coupled to the first input transistor. The second cascode transistor is coupled to the second input transistor and the first cascode transistor. The first current mirror circuit is coupled to the first cascode transistor, the second cascode transistor, and the first input terminal. The second current mirror circuit is coupled to the first cascode transistor, the second cascode transistor, and the second input terminal.

A first transmission line and a second transmission line that are connected in series to each other are disposed at different positions in a thickness direction of a substrate. A third transmission line is disposed between the first transmission line and the second transmission line in the thickness direction of the substrate. The third transmission line includes a first end portion connected to one end portion of the first transmission line, and a second end portion that is AC-grounded. The first transmission line and the second transmission line are electromagnetically coupled to the third transmission line.

A semiconductor device including an error amplifier configured to receive a voltage of an output node and a reference voltage, a flipped voltage follower (FVF) circuit configured to receive an output of the error amplifier and maintain the voltage of the output node at the reference voltage, and a bias current control circuit configured to receive first to third mode signals, control a magnitude of a bias current flowing through the FVF circuit based on the first to third mode signals, control the bias current of a first magnitude, based on the first mode signal, control the bias current of a second magnitude smaller than the first magnitude, based on the second mode signal, and control the bias current of a third magnitude smaller than the second magnitude, based on the third mode signal.