Phantom-powered inline preamplifiers capable of variable impedance loading are disclosed with unique adjustable interfaces. By enabling a user to adjust impedance loading from an actively-powered audio preamplifier which takes a microphone electrical signal or another sound source signal as an input, this unique audio preamplifier design with various adjustable impedance loading interface configurations can change sound characteristics according to the user's preference in a recording, production, or live concert environment. In addition, a high pass filter incorporated in a preamplifier with the variable impedance loading feature allows the user to further customize sound characteristics in the recording environment. This novel inline preamplifier, which may be standalone or integrated into a microphone casing, is powered via a microphone cable from a component (e.g. another preamplifier) providing the phantom power. This inline preamplifier may be connected to a conventional microphone and receive phantom-power into the inline preamplifier from a conventional preamplifier.

A driver circuit arrangement for driving a load and a differential drive arrangement thereof are provided. The driver circuit arrangement employs a dual feedback configuration with a feedback resistor and a current sensor feedback arrangement. The current sensor feedback arrangement provides a current feedback path from the amplifier output to the amplifier input, and has a current sensor resistor connected in an output current path of the driver circuit arrangement. A current feedback amplifier is present connected to the current sensor resistor and to the amplifier input.

A high CMRR neural signal amplifier is configured for supply rail common mode feedback (SR-CMFB) whereby a set of CMFB signals is provided to supply rails of front end LNAs. High CMRR is maintained through buffering outputs of front end signal LNAs and a reference LNA coupled to signal and reference inputs of second stage amplifiers, respectively; and buffering the reference LNA output using an active/guard buffer pair, whereby across a plurality of distinct multiplexing time intervals, during each multiplexing time interval one buffer of the pair functions as an active buffer that drives second stage amplifier reference inputs corresponding to second stage amplifier outputs being multiplexed to a set of multiplexor outputs, and the other buffer of the pair functions as a guard buffer coupled to other second stage amplifier reference inputs corresponding to second stage amplifier outputs not being multiplexed to the set of multiplexor outputs.

An apparatus, system, and method are disclosed for compensating input offset of an amplifier having first and second amplifier output nodes. The method comprises generating a proportional-to-absolute temperature (PTAT) current, generating a complementary-to-absolute temperature (CTAT) current, and selecting, based on the input offset, one of the first and second amplifier output nodes into which a compensation current is to be coupled. The compensation current is based on a selected one of the PTAT current and CTAT current.

A driving device with correction function is provided herein and utilizes a sensing resistor to detect the variation in an operation amplifier. A signal generated by an offset voltage correction circuit is fed back to the operation amplifier and the offset voltage of the abnormal input in the operation amplifier is corrected to be zero so as to keep the operation amplifier under the best performance condition. The driving device implements in the wireless charger driving system can enhance the accuracy of the current value and can achieve good output performance and better system stability.

A headphone driver, a sound processor that incorporates the headphone driver and a computing system that incorporates the headphone driver are provided. The headphone driver includes an amplifier having an input terminal and an output terminal, an R-2R ladder network provided with an input signal and connected to the input terminal of the amplifier, and a feedback resistor group connected to the input terminal and to the output terminal of the amplifier. The R-2R ladder network includes a plurality of resistor branches and a first attenuator that is connected between the plurality of resistor branches.

A current sense amplifier circuit of a circuit device includes: an operational amplifier; a first resistor provided between one end of a shunt resistor and a first node, a first switch provided between the first node and a first input node, a second resistor provided between another end of the shunt resistor and a second node, a second switch provided between the second node and a second input node, a third resistor provided between a constant voltage node and the third node, a third switch provided between the third node and the first input node, a fourth resistor provided between the constant voltage node and a fourth node, and a fourth switch provided between the fourth node and the second input node.

A novel phantom-powered JFET gain circuit that improves audio clarity and linearity, while reducing a high-gain burden, noise, and distortion from a sole usage of a conventional preamplifier, is disclosed. In one embodiment, the novel phantom-powered JFET gain circuit is encased as a standalone box that connects to a microphone on one end and a conventional preamplifier unit or another conventional audio processing unit on another end. In another embodiment, the novel phantom-powered JFET gain circuit is integrated into a portable electronic device or another consumer electronic device with a microphone to provide an earliest-stage gain in a microphone-captured audio signal processing pathway. Yet in another embodiment, the novel phantom-powered JFET gain circuit is integrated into a preamplifier unit and provides the earliest-stage gain in a microphone-captured audio signal processing pathway, prior to additional and conventional signal amplification by the preamplifier unit.

Embodiments generally relate to a conversion arrangement, a driver arrangement, and a method of producing a complementary complementary metal-oxide-semiconductor (CMOS) output signal for driving a modulator device. The conversion arrangement includes a differential amplifier configured to produce a first amplified signal based on the differential input signal, and at least two transimpedance amplifiers (TIAs) coupled with respective outputs of the differential amplifier and configured to produce a second amplified signal based on the first amplified signal. Respective bias voltages for the TIAs are based on the first amplified signal. The conversion arrangement further includes a common-mode feedback arrangement coupled with outputs of the TIAs and configured to control the first amplified signal based on the second amplified signal, thereby controlling the bias voltages, wherein the complementary CMOS output signal is based on the second amplified signal.

Apparatus and method for an output stage of an amplifier are disclosed. A current source circuit provides current to a transistor connected to the amplifier output node to produce output voltage, and the current source circuit has two current mirror paths, one of which replicates the output voltage at the output node. As the output voltage approaches rail, more current is steered to the current mirror path not replicating the output voltage and provides additional current or voltage necessary to keep the current source circuit operational.