A converter circuit includes first and second input terminals, control circuitry, and a storage capacitor. The first and second input terminals are configured for connection to an AC power supply to receive an AC signal. The control circuitry is coupled to the first and second input terminals. A terminal of the storage capacitor is coupled to an output node of the control circuitry. The storage capacitor is charged by the control circuitry and configured for use as a DC power source. The control circuitry is configured to couple the first input terminal to the storage capacitor during a portion of a positive half-cycle of the input AC signal to charge the storage capacitor and to decouple the first input terminal from the storage capacitor during an entirety of each negative half-cycle of the input AC signal, to thereby prevent discharging of the storage capacitor by the input AC signal.

In a memory, a first node holds first data from a first cell. A second node holds second data from a second cell near the first cell. A differential circuit includes a first current path passing a first current corresponding to a voltage of the first node and a second current path passing a second current corresponding to a voltage of the second node, and outputs an output signal corresponding to a voltage difference between the first and the second nodes from an output part. A first register latches the output signal and output the signal as a hold signal. A first offset part is connected to the first current path and offsets the first current when the hold signal has a first logic level. A second offset part is connected to the second current path and offsets the second current when the hold signal has a second logic level.

An analog-to-digital converter includes a sample hold circuit configured to receive an analog input signal based on an operating mode, the operating mode being one of at least two modes including a sample mode and a hold mode. The sample hold circuit includes a first transistor including a control terminal and a first terminal, the first transistor configured to receive a control signal via the control terminal and receive the analog input signal via the first terminal. The analog-to-digital converter further includes a bootstrap switch operationally connected to the control terminal and the first terminal of the first transistor, the bootstrap switch configured to form a first current path from a power source based on the analog input signal and a boosted voltage of the control terminal of the first transistor in the sample mode, the control terminal bing along the first current path in the sample mode.

An apparatus includes a sample-and-hold (S/H) circuit. The S/H circuit includes a first switch coupled to provide an input signal to be sampled, and a second switch coupled to the first switch and to a first capacitor. The S/H circuit further includes a third switch coupled to the second switch and to a second capacitor, and a fourth switch to selectively couple to ground a node between the first and second switches.

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.

A memory controller includes a voltage driver and a voltage comparator. The voltage driver applies a variable voltage to a selected line of a crossbar array to determine a first measured voltage that drives a first read current through a selected memory cell of the crossbar array. The voltage driver applies the variable voltage to the selected line to determine a second measured voltage that drives a second read current through the selected memory cell. The voltage comparator then determines a voltage difference between the first measured voltage and the second measured voltage and to compare the voltage difference with a reference voltage difference to determine a state of the selected memory cell. The crossbar array comprises a plurality of row lines, a plurality of column lines, and a plurality of memory cells. Each memory cell is coupled between a unique combination of one row line and one column line.

An analog store-digital read (ASDR) ultrasound beamformer architecture performs the task of signal beamforming using a matrix of sample/hold cells to capture, store and process instantaneous samples of analog signals from ultrasound array elements and this architecture provides significant reduction in power consumption and the size of the diagnostic ultrasound imaging system such that the hardware build upon ASDR ultrasound beamformer architecture can be placed in one or few application specific integrated chips (ASIC) positioned next to the ultrasound array and the whole diagnostic ultrasound imaging system could fit in the handle of the ultrasonic probe while preserving most of the functionality of a cart-based system. The ASDR architecture provides improved signal-to-noise ratio and is scalable.

A sense amplifier circuit includes a sampling capacitor coupled to the input of an inverting amplifier. The output of the inverting amplifier is coupled to a transistor that includes a current terminal. The memory read operation includes two phases. During a first phase, a terminal of the capacitor is coupled to a first cell. During a second phase, the terminal of the capacitor is coupled a second cell.

Aspects of various embodiments of the present disclosure are directed to applications utilizing voltage sampling. In certain embodiments, a sample and hold circuit is configured to sample voltages that exceed a tolerance voltage of components. The circuit includes a first and a second capacitors. In a first mode, a voltage difference between an input node and a first reference voltage is sampled using the first capacitor. Also in the first mode, a voltage stored by the second capacitor is referenced to a second reference voltage and provided to a first output node. In a second mode, a voltage difference between an input node and a first reference voltage is sampled using the second capacitor. Also in the second mode, a voltage stored by the first capacitor is referenced to the second reference voltage and provided to a second output node.

A sample-and-hold circuit is provided that includes a plurality of sample-and-hold branches arranged in parallel and each including a buffer and a sample-and-hold block including one or more sample-and-hold cells. The sample-and-hold circuit further includes a clock and timing circuit arranged for setting an adaptable time delay to enable sampling and sampling phase for each sample-and-hold block. The time delay of at least one sample-and-hold block can be set to value bigger than one sampling clock period.