A micro-device for measuring impedance of animal tissue by simulating alternating current with low power direct current to provide a miniaturized device that carries out electrical impedance procedures.

A multiplexer includes a charging circuit; a plurality of sampling switches receiving a plurality of input signals; and a plurality of boosting circuits connected between the sampling switches and the charging circuit and sharing the charging circuit. First and second charging switches of the charging circuit are controlled by a first clock signal. Each of the boosting circuits includes a first boosting switch connected to a first node of the charging circuit and a gate of one of the sampling switches, a second boosting switch connected between a second node of the charging circuit and the one sampling switch, and a level shifter configured to control the first boosting switch and the second boosting switch in response to a second clock signal and a selection signal.

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.

Disclosed is a sample and hold circuit and method capable of amplifying an input signal. The method includes: in a sample phase, receiving a first (second) input signal with top electrodes of first (second) capacitors, and receiving the second (first) input signal with all bottom electrode(s) of at least a part of the first (second) capacitors; in a hold phase, stopping receiving the first (second) input signal with the top electrodes of the first (second) capacitors, and receiving a first (second) group of reference signals with the bottom electrodes of the first (second) capacitors, so that the first (second) capacitors provide a first (second) sample voltage on the top electrodes of the multiple first (second) capacitors through charge redistribution, wherein the first and second input signals are a pair of differential signals and they are opposite to each other.

An analog delay line includes a clock generator, an analog sampling circuit, a bank of analog memory cells, a memory controller, an analog readout circuit, and an analog multiplexer. The clock generator is configured to output plural reception clock signals of different frequencies and plural transmission clock signals of different frequencies, the transmission clock signals offset in accumulated phase relative to the reception clock signals. The analog sampling circuit is controlled by at least one of the reception clock signals, and is configured to output a sequence of sampled voltages of an analog input signal. The memory controller is configured to control a write operation at a write frequency of at least one of the reception clock signals and a read operation at a read frequency of at least one of the transmission clock signals. The write operation is for sequentially storing the sampled voltages received from the analog sampling circuit in the bank of analog memory cells, and the read operation is for sequentially reading the sampled voltages from the bank of analog memory cells. The analog readout circuit is configured to buffer the sampled voltages read from the bank of analog memory cells. The analog multiplexer is controlled by at least one of the transmission clock signals, and is configured to multiplex the sampled voltages buffered by the readout circuit to generate an analog output signal. A sampling rate of the analog input signal is within a factor of 2 of a sampling rate of the analog output signal.

An example sample-and-hold circuit includes a first and second input resistors, each having first and second terminals; first and second transistors coupled in series between the second terminals of the first and second input resistors; and third and fourth input resistors, each having first and second terminals; and third and fourth transistors coupled in series between the second terminals of the third and fourth input resistors. The control terminals of the first and third transistors are coupled together, and the control terminals of the second and fourth transistors are coupled together.

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.

A circuit configured to compute matrix multiply-and-add calculations that includes a digital-to-time converter configured to receive a digital input and output a signal proportional to the digital input and modulated in time-domain associated with a reference time, a memory including a crossbar network, wherein the memory is configured to receive the time modulated signal from the digital-to-time converter and output a weighted signal scaled in response to network weights of the crossbar network and the time modulated input signal, and an output interface in communication with the crossbar network and configured to receive its weighted output signal and output a digital value proportional to at least the reference time using a time-to-digital converter.

Systems, apparatuses and methods include technology that identifies whether a product of first and second digital numbers is associated with a positive value or a negative value. During a first clock phase, the technology sets a first reference voltage to have a first value or a second value based on whether the product is associated with the positive value or the negative value. During the first clock phase, the technology controls switches to supply the first reference voltage to first plates of capacitors. Each of the capacitors includes a respective first plate of the first plates and a second plate. Further, during the first clock phase, the technology controls the switches based on the first digital number to electrically connect at least one of the second plates to the first reference voltage and electrically connect at least one of the second plates to a second reference voltage.

Systems and methods for a capacitor based resistive processing unit with symmetrical weight updating include a first capacitor that stores a charge corresponding to a weight value. A readout circuit reads the charge stored in the first capacitor to apply a weight to an input value corresponding to an input signal using the weight value to produce an output. An update circuit updates the weight value stored in the first capacitor, including a second capacitor in communication with the first capacitor to transfer an amount of charge to the first capacitor according to an error of the output by changing a voltage difference across the first capacitor by a voltage change corresponding to the amount of charge, the voltage difference corresponding to the charge stored in the first capacitor.