Various embodiments of the present technology may provide methods and apparatus for a track-and-hold amplifier configured to sample and amplify an analog signal. Methods and apparatus for a track-and-hold amplifier according to various aspects of the present invention may provide an isolation circuit configured to isolate transient current in a track-and-hold capacitor during a track phase. According to various embodiments, selective activation of the isolation circuit provides a settling time that is independent of the gain of the amplifier.

A current stimulator includes a first current generation circuit configured to generate a first current, injectable into a cranial nerve cell, through a current mirroring based on a plurality of transistor pairs; and a second current generation circuit, driven by a clock, configured to generate a second current smaller than the first current by controlling a charge rate based on a voltage difference between terminals of a capacitor. A first output impedance of the first current generation circuit and a second output impedance of the second current generation circuit have a magnitude greater than or equal to a predetermined ratio to a load impedance corresponding to the cranial nerve cell.

A conversion circuit for converting a current signal into a first output voltage signal, where the current signal flows through a sensing component, is provided. The conversion circuit includes: a first current eliminating circuit, configured to eliminate a first current in the current signal. The first current eliminating circuit includes: a current sample and hold circuit; and a current driving circuit, coupled between the sensing component and the current sample and hold circuit; a second current eliminating circuit, coupled to the sensing component and configured to eliminate a second current in the current signal; and an integrating circuit, coupled to the sensing component and configured to integrate a third current in the current signal, and output a first input voltage signal between a first integration output terminal and a second integration output terminal.

A follow-hold switch circuit comprising: a follower; a sampling sub-circuit for voltage sampling; a bootstrap-control sub-circuit, which provides a bootstrap voltage to the sampling sub-circuit when the circuit is in a following state; a sampling-switch-control sub-circuit, which provides a common-mode voltage to a bootstrap capacitor in the bootstrap-control sub-circuit when the circuit is in a holding state; the follower is connected to an output of the sampling sub-circuit; the sampling sub-circuit is connected to the bootstrap-control sub-circuit and the sampling-switch-control sub-circuit respectively through a sampling switch; the present disclosure can effectively improve the linearity of sampling switches.

A method for implementing nonvolatile memory array logic includes configuring a crosspoint memory array in a first configuration and applying an input voltage to the crosspoint array in the first configuration to produce a setup voltage. The crosspoint array is configured in a second configuration and an input voltage is applied to the crosspoint array in the second configuration to produce a sense voltage. The setup voltage and the sense voltage compared to perform a logical operation on data stored in the crosspoint array. A system for performing nonvolatile memory array logic is also provided.

The disclosure provides a circuit. The circuit includes a gain stage block. The gain stage block is coupled to an input voltage through a first switch. A first capacitor is coupled between the first switch and a ground terminal. A second capacitor is coupled between the first switch and a second switch. A third switch is coupled between the second capacitor and a fixed terminal of the gain stage block.

An embodiment includes an analog-to-digital converter device. A device may include a first track and hold amplifier configured to receive an analog input signal. The device may also include a plurality of paths coupled to an output of the first track and hold amplifier. Each path of the plurality of paths includes a second track and hold amplifier coupled to the first track and hold amplifier, and a successive approximation register analog-to-digital converter coupled to an output of the second track and hold amplifier. The successive-approximation analog-to-digital converter may include heterojunction bipolar transistors, a comparator, R-2R DAC, and a SiGe BiCMOS quasi-CML SAR register and sequencer.

The present embodiments provide an analog to digital converter, including a beam splitter, M photodetectors, M amplifier modules, and an encoder. Each output end of the beam splitter is corresponding to an input end of a photodetector, an output end of each photodetector is connected to an input end of an amplifier module, and an output end of each amplifier module is connected to an input end of the encoder. The beam splitter splits an inputted analog optical signal into M optical signals, outputs each optical signal to a corresponding photodetector to convert each optical signal into a current signal, inputs each current signal to a corresponding amplifier module to generate an output voltage, and outputs the output voltage to a corresponding input end of the encoder.

An embodiment includes a track and hold amplifier device. A device may include an emitter follower transistor coupled to each of an input and an output. The device may also include a charging node coupled between the output and a voltage supply, wherein the charging node is also coupled to the input via the emitter follower transistor. Further, the device may include a cascode switch coupled to each of the input and the output. The cascode switch may be configured to cause the emitter follower transistor to operate in a conductive state and charge the charging node during a track mode. The cascode switch may also be configured to cause the emitter follower transistor to operate in a non-conductive state to isolate the charging node from the input during a hold mode. The cascode switch may include a MOS-HBT transistor combination operating in class AB mode.

A switch circuit for use in a single-ended switched-capacitor circuit for front-end circuitry of a sensor device is disclosed. The switch circuit comprises a first transistor and a second transistor having a same channel-type as the first transistor. A first node is connected to a source of the first transistor and a drain of the second transistor and a second node is connected to a drain of the first transistor and a source of the second transistor. Also disclosed is a sampling circuit comprising the switch circuit and a sampling capacitor, wherein the switch circuit is configurable to electrically couple the sampling capacitor to an integrator circuit or to a voltage reference. An integrated circuit device and a light to frequency converter or light sensor comprising the switch circuit is also disclosed.