8 results about "Analog multiplier" patented technology

The present invention discloses a four-quadrant analog multiplier circuit and a control method based on a memristor. The analog multiplier circuit based on a memristor mainly includes a sign conversion circuit, an external control circuit, a memristor control circuit, a Cascode current mirror circuit composed of NMOS transistors, and a Cascode current mirror circuit composed of PMOS transistors. Among them, the Cascode current mirror circuit composed of NMOS transistors and the memristor control circuit form a first-quadrant memristor analog multiplier circuit, and the Cascode current mirror circuit composed of PMOS transistors and the memristor control circuit form a second-quadrant memristor analog multiplier circuit. The sign conversion circuit mainly converts the input signal into a signal in the first and second quadrants and inputs the signal into the corresponding quadrant memristor analog multiplier circuit. After receiving a positive input signal, the external control circuit outputs the control voltage required by the memristor analog multiplier circuit. Compared with the existing analog multiplier circuit, the memristor analog multiplier has higher linearity and accuracy, and the circuit structure and operation process are relatively simple.

This application discloses a precision capacitance sensing system, comprising a modulation signal source, a sensitive probe, a differential transformer bridge, a signal amplification link, an analog multiplier, and a low-pass filter circuit, all connected in sequence. It also includes a demodulation reference signal source, the output of which is connected to the second input of the analog multiplier. The demodulation reference signal source is used to generate a multi-frequency combination demodulation reference signal, which is composed of a fundamental frequency component and at least two harmonic components superimposed. This invention also discloses a precision capacitance sensing method. By employing a specially designed demodulation reference signal, this application ensures that the system output remains constant within a continuously varying range of the demodulation phase difference, thereby achieving complete insensitivity to phase difference fluctuations and effectively overcoming the performance bottleneck that has long constrained high-precision capacitance sensing.

The utility model relates to the field of RFID technology, specifically is a kind of high-frequency label FSK signal demodulation circuit that can realize high-frequency RFID label long-distance reading, it is characterized by being equipped with envelope detection circuit, active band-pass filter amplification circuit, phase shift circuit, analog multiplier circuit, low-pass filter amplification circuit and comparison decision circuit, wherein, envelope detection circuit receives data from antenna and data is sent into active band-pass filter amplification circuit, and one way output of active band-pass filter amplification circuit will received data send into analog multiplier circuit, and another way of active band-pass filter amplification circuit will received data send into phase shift circuit.

An analog multiplier circuit for performing multiply and scaling operations comprises a differential amplifier, at least two storage circuits, a summing circuit; and an exponentiating circuit. In response to receiving a first control signal, receiving as input an analog signal output by the differential amplifier and storing a value derived from the analog signal. In response to receiving a second control signal, outputting a storage analog signal derived from the stored value. The summing circuit receives storage analog signals from the storage circuits, and outputs an analog signal substantially proportional to a sum of the input storage analog signals.

The utility model belongs to a kind of measurement circuit of full electronic board transformer phase difference, comprising: the alternating current power supply of providing primary voltage to transformer, the direct current power supply of power supply for digital circuit, primary sampling circuit, secondary sampling circuit, filter circuit, analog multiplier, processor and display. The alternating current power supply provides voltage to transformer primary, by primary sampling circuit and secondary sampling circuit, the primary and secondary voltage of transformer is sent into the input end of analog multiplier after filtering by filter circuit, the output signal is sent to processor, analog signal is converted into digital signal, and the amplitude of positive and negative half wave of comparison signal is passed through, the phase difference of primary and secondary is accurately calculated, to show in display in the form of number, to be able to accurately measure the phase of transformer in full electronic interlocking circuit board, improve the yield of product batch production.

A kind of ultrasonic sensor based on partial discharge, comprising: sequentially connected with ultrasonic signal input module, three-stage amplification circuit module, band-pass filter circuit module, frequency reduction circuit module, low-pass filter circuit module and output module.The working principle is: input module converts the high-frequency ultrasonic wave generated by partial discharge into weak electric signal;After signal amplitude is significantly improved by three-stage amplification circuit, by band-pass filter circuit, out-of-band noise is filtered out, and effective discharge frequency band signal is retained;Frequency reduction circuit converts ultrasonic signal into low-frequency signal by mixing frequency with LC frequency reduction through analog multiplier;Further purification is carried out by low-pass filter circuit, and finally converted into audible sound by output module.The present application integrates signal acquisition and processing functions, solves the problem of external equipment in prior art, and has the advantages of high sensitivity, strong anti-interference ability, convenient on-site rapid and intuitive detection.

The application discloses a ReLU type segmented nonlinear multi-stable memristor simulator, which comprises an operational amplifier unit, an integral feedback unit, a ReLU conversion unit and a controllable multi-stable output unit; the operational amplifier unit performs addition operation on an input signal and a signal generated by the integral feedback unit, and transmits the signal to the integral feedback unit to generate an internal state integral signal; the ReLU conversion unit performs nonlinear conversion on the integral signal; and the controllable multi-stable output unit outputs a memristor current through an analog multiplier and a proportional resistor from the input signal and the ReLU conversion signal. Through numerical simulation and circuit experiment verification, the volt-ampere characteristics of the memristor simulator meet the three essential characteristics of the memristor, and different hysteresis loops are exhibited under different initial values, so that the memristor simulator has the multi-stable characteristics, the circuit structure is clear, the parameters are adjustable, and the memristor simulator is easy to implement in engineering and can be used in scenes such as chaotic circuits and neural network construction.