Embodiments of the disclosure are drawn to apparatuses and methods for a chopper instrumentation amplifier. For a variety of applications, such as testing the resistance of connections between layers of a memory, it may be desirable to provide a high gain instrumentation amplifier. A chopper instrumentation amplifier may provide a high gain while allowing a wide range of common input voltages and a canceling an offset on the amplifier. An example chopper instrumentation amplifier of the present disclosure may include a plurality of amplifiers including chopper amplifiers and non-chopper amplifiers. The chopper amplifiers may use chopper circuits to cancel out an offset voltage of the amplifiers. Low pass filters may be used to minimize the impact of the chopper amplifiers.

An N-path filter with one or more branches selectively coupled to a shared circuit node includes a first branch having a first feedback path and a second feedback path. The first feedback path includes a Miller amplifier having an input coupled to an input voltage and a first capacitor coupled to both the input voltage and an output of the Miller amplifier. The second feedback path includes a node in common with the first feedback path. The second feedback path also includes a first high pass filter coupled to the output of the Miller amplifier and a second capacitor coupled to both the first capacitor and the first high pass filter.

Systems for detecting light (e.g., in a flow stream) are described. Light detection systems according to embodiments include a photodetector, an input modulator configured to modulate signal input into the photodetector and an output modulator configured to modulate signal output from the photodetector. Photodetector arrays having a plurality of light detection systems, e.g., as described, are also provided. Methods for matching output signals from two or more photodetectors (e.g., a plurality of photomultiplier tubes in a photodetector array) are also described. Flow cytometer systems and methods for detecting light from a sample in a flow stream are provided. Aspects further include kits having two or more of the subject light detection systems.

An architecture of radio frequency front-end includes a power amplifier module integrated duplexer (PAMiD), an antenna and at least one tunable matching network; herein, the PAMiD includes a power amplifier, and the at least one tunable matching network is located between the power amplifier and the antenna, and is configured to adjust the impedance of the output end of the power amplifier and/or the impedance of the input end of the antenna.

An electronic device may include wireless circuitry with a processor, a transceiver, an antenna, and a front-end module coupled between the transceiver and the antenna. The front-end module may include one or more power amplifiers for amplifying a signal for transmission through the antenna. A power amplifier may include multiple amplifier stages. Current sharing or reuse may occur between two amplifier stages in the power amplifier via a current flow path between the two amplifier stages. A power supply voltage line may be connected to the current flow path and may provide the downstream amplifier stage with a supplemental supply current based on which the downstream amplifier stage can amplify a radio-frequency signal received from the upstream amplifier stage.

The present disclosure provides an inductive magnetic sensor, which includes a signal pre-amplifying measurement circuit, a feedback loop, a magnetic core and coil group, a low-noise autozero processing circuit, and an output protection module. The magnetic core and coil group is electrically connected between the signal pre-amplifying measurement circuit and the feedback loop, the signal pre-amplifying measurement circuit comprises the low-noise autozero processing circuit, and the feedback loop and the low-noise autozero processing circuit are electrically connected to the output protection module respectively. By introducing the resonant notch filter, it may extend the passband to the low frequency, and extend the low-frequency characteristic of the magnetic sensor, to obtain a better low-frequency magnetic sensor. The present disclosure further provides an electromagnetic prospecting equipment.

Embodiments of the present disclosure provide a chopper amplifier circuit that includes an operational amplifier, and a notch filter to be operated by a chopping pulse. The notch filter has a first branch that has a first capacitor, and a second branch that has a second capacitor. A chopping delay switch is connected to the first branch and the second branch of the notch filter. A control circuit is to close the chopping delay switch to short-circuit the first branch and the second branch of the notch filter to each other. The control circuit is to detect establishment of feedback signal at the chopper amplifier. The control circuit is to open the chopping delay switch, responsive to detecting establishment of the feedback signal at the chopper amplifier.

Provided are, among other things, systems, apparatuses methods and techniques for converting digital data to radio-frequency (RF) signals. One such apparatus includes a reactive-impedance network within which the levels of multiple binary waveforms are individually boosted, before being combined to produce a single, composite output signal.

The present disclosure relates to Class D amplifier circuitry comprising: an input for receiving an input signal; first and second output nodes for driving a load connected between the first and second output nodes. A first driver stage is provided for switching the first node between a first supply rail and a second supply rail, and a second driver stage is provided for switching the second node between the first supply rail and the second supply rail. The Class D amplifier circuitry also includes first driver control circuitry configured to receive a first carrier wave and control the switching of the first driver stage based in part on the first carrier wave; second driver control circuitry configured to receive a second carrier wave and control the switching of the second driver stage based in part on the second carrier wave; and a carrier wave generator configured to provide the first carrier wave and the second carrier wave. A phase shift between the first carrier wave and the second carrier wave is adjustable responsive to a mode control signal.

Multi-level envelope trackers with an analog interface are provided herein. In certain embodiments, an envelope tracking system for generating a power amplifier supply voltage for a power amplifier is provided. The envelope tracking system includes a multi-level supply (MLS) DC-to-DC converter that outputs multiple regulated voltages, and an MLS modulator that controls selection of the regulated voltages over time based on an analog envelope signal corresponding to an envelope of the RF signal amplified by the power amplifier.