A threshold voltage continuously adjustable current circuit based on memristor

Abstract

The application discloses a threshold voltage continuous adjustable current circuit based on a memristor, which comprises a single-chip microcomputer, a rectifier circuit, a memristor regulating circuit and a host computer Uart serial communication circuit. First, the single-chip microcomputer receives a specific threshold voltage input by the host computer through the Uart serial port, and calculates the required resistance value of the memristor; second, the single-chip microcomputer regulates a PMOS tube of an inverter in the rectifier circuit, and closes the power supply of the PMOS tube, so that the rectifier circuit stops working; then, the single-chip microcomputer controls the memristor regulating circuit to work, and after the resistance value of the memristor reaches the preset value, the single-chip microcomputer controls the memristor regulating circuit to stop working, so that the resistance value of the memristor is fixed, and meanwhile, the single-chip microcomputer restores the power supply of the PMOS tube of the inverter in the rectifier circuit, so that the rectifier circuit continues to rectify the input signal; finally, the output signal is returned to the single-chip microcomputer for detection, so as to realize the closed-loop monitoring of the rectified signal and more accurate continuous adjustment of the threshold voltage.

Description

Technical Field

[0001] The present invention relates to a rectifier circuit with continuously adjustable threshold voltage, and in particular to a rectifier circuit with continuously adjustable threshold voltage based on a memristor. Background Art

[0002] The primary function of a rectifier circuit is to convert an input signal into a stable and reliable output signal. In analog circuits, rectifier circuits can be used for signal denoising, converting noisy input signals into pure output signals. In digital circuits, rectifier circuits can be used to design pulse signal generators to produce specific pulse signals. In industrial electrical equipment, rectifier circuits convert alternating current (AC) to direct current (DC), providing a stable DC power supply for DC motors. In automated control systems, rectifier circuits can also be used for parameter monitoring, triggering alarm signals when preset parameters exceed their thresholds. Therefore, rectifier circuits have broad application potential in a variety of system fields.

[0003] Traditional rectifier circuits usually use Schmitt trigger circuits, such as Figure 1 It consists of resistors R1-R2, PMOS tubes Q1, Q3 and NMOS tubes Q2, Q4. Its working principle is to convert the input signal based on the hysteresis characteristics of the Schmitt trigger circuit. in It is connected to the first stage inverter composed of resistor R1, PMOS tube Q1 and NMOS tube Q2; PMOS tube Q3 and NMOS tube Q4 form the second stage inverter and are connected to the output signal V out resistor R2 is connected between the output terminal of the second-stage inverter and the input terminal of the first-stage inverter.

[0004] exist Figure 1 In the rectifier circuit, when the signal is input, the final output voltage is determined by comparing the input signal voltage with the forward or reverse threshold voltage of the rectifier circuit. DD Greater than the threshold voltage V of the PMOS and NMOS tubes th When the sum of the two, according to Kirchhoff's current law, the input voltage of the first stage inverter V A It can be expressed as: When the inverter input voltage V A Greater than the threshold voltage V of the MOS tube th When the output signal V out is high level, otherwise the output signal V out Is low level; that is, when the input voltage V in Greater than When the output voltage V out Flip to high level; when the input voltage V in Lower than When the output voltage V out is low, the output voltage V DD is high. Under the action of the rectifier circuit, the input signal can be rectified, and the corresponding square wave signal is generated. The forward or reverse threshold voltage during rectification can be determined by adjusting the resistance R1, R2 in the rectifier circuit and the power supply V DD of the inverter.

[0005] The traditional rectifier circuit usually uses adjustable resistance, such as linear potentiometer or multi-turn potentiometer, to change the resistance value in the rectifier circuit to realize the adjustment of the forward or reverse threshold voltage in the rectifier circuit. However, the linear potentiometer has the disadvantages of mechanical wear, non-linearity, low precision, etc., and the multi-turn potentiometer has the disadvantages of high cost, large size and low durability, etc.

[0006] Currently, the memristor is the fourth basic electronic element in addition to resistance, inductance and capacitance. The memristor has resistance plasticity, that is, the resistance value can change according to the voltage applied to the memristor, and the resistance value remains unchanged after power-off. The resistance plasticity of the memristor has directionality, that is, the application of opposite voltage can cause opposite change of the resistance value. At the same time, the voltage threshold type memristor has the characteristic that only when the voltage across the memristor exceeds the threshold value, the resistance value of the memristor changes. In addition, the memristor also has the advantages of fast speed, nanometer size, low power consumption, high reliability, compatibility with CMOS and easy large-scale integration. Therefore, the memristor is suitable for application in hardware circuit design and can replace adjustable resistance elements such as linear potentiometer or multi-turn potentiometer.

[0007] Based on the resistance plasticity and threshold characteristics of the memristor, the present application proposes a threshold voltage continuously adjustable flow circuit based on the memristor, which realizes continuous control of the threshold voltage of the rectifier circuit and also meets the design requirements of high precision, small size, low power consumption and high speed. SUMMARY

[0008] The present application proposes a threshold voltage continuously adjustable flow circuit based on the memristor, which uses voltage threshold type memristor to replace the potentiometer in the traditional rectifier circuit, and uses a single-chip microcomputer to control the memristor control circuit, realizes continuous adjustment of the resistance value of the memristor, so that the forward or reverse threshold voltage of the rectifier circuit when processing the input signal can be continuously adjustable.

[0009] The present application is realized by the following technical scheme: a threshold voltage continuously adjustable flow circuit based on the memristor, which comprises a single-chip microcomputer, a rectifier circuit, a memristor control circuit and an upper computer Uart serial communication circuit.

[0010] Firstly, the single-chip microcomputer can receive the specific threshold voltage input by the host computer through the serial port, and calculate the required resistance value of the memristor by the single-chip microcomputer; secondly, the single-chip microcomputer controls the PMOS tube of the inverter in the rectifier circuit to turn off its power supply, so that the rectifier circuit stops working; then, the single-chip microcomputer controls the memristor control circuit to work, so that the resistance value of the memristor reaches the preset value, and then the single-chip microcomputer controls the memristor control circuit to stop working, so that the resistance value of the memristor is fixed, and at the same time the single-chip microcomputer restores the power supply of the PMOS tube of the inverter in the rectifier circuit, so that the rectifier circuit continues to rectify the input signal; finally, the output signal can be returned to the single-chip microcomputer for detection, realizing closed-loop monitoring of the rectified signal and more accurate continuous adjustable threshold voltage.

[0011] The rectifier circuit is composed of the memristor M1, the resistor R1, the PMOS tubes Q1 and Q3, the NMOS tubes Q2 and Q4, and works based on the hysteresis principle of the circuit. The PMOS tube Q1 and the NMOS tube Q2 constitute the first stage inverter, and the PMOS tube Q3 and the NMOS tube Q4 constitute the second stage inverter. The source electrodes of Q1 and Q3 are connected in parallel to the P1.5 pin of the single-chip microcomputer, and the single-chip microcomputer controls the power supply of the PMOS tube of the inverter through the P1.5 pin. When the rectifier circuit works normally, the voltage value between the two ends of the memristor M1 is lower than the threshold voltage of the memristor, so that the resistance value of the memristor is fixed. The M1, R1 and the power supply of the inverter constituting the rectifier circuit are used to regulate the forward or reverse threshold voltage in the rectification process. According to Kirchhoff's current law, the input voltage V A of the first stage inverter can be expressed as: When the input voltage V in is greater than , the output voltage V out is flipped to high level; when the input voltage V in is lower than , the output voltage V out is flipped to low level. Under the action of the rectifier circuit, the input signal can be rectified and the corresponding square wave signal can be generated. The threshold voltage during the rectification of the input signal can be determined by the memristor M1, the resistor R1 and the power supply V DD of the inverter in the rectifier circuit. By changing the resistance value of the memristor M1, the forward or reverse threshold voltage of the rectifier circuit can be changed.

[0012] The memristor control circuit is composed of the positive power supply V CC , the negative power supply V EE and a plurality of NMOS tubes Q5-Q7, and is used to adjust the resistance value of the memristor M1. The single-chip microcomputer adjusts the conduction state of the NMOS tube connected thereto by controlling the level of the output pin. The positive power supply V CC and the negative power supply V EEThe NMOS tube Q5 and the NMOS tube Q7 connected to the negative electrode of the memristor are turned on when the single-chip microcomputer control is connected to V CC When the NMOS tube Q5 connected to the positive electrode of the memristor and the NMOS tube Q7 connected to the negative electrode of the memristor are turned on, the voltage of the positive electrode of the memristor will exceed the positive threshold voltage, thereby causing the resistance of the memristor to decrease; on the contrary, when the NMOS tube Q6 connected to V EE When the NMOS tube Q5 connected to the positive electrode of the memristor and the NMOS tube Q7 connected to the negative electrode of the memristor are turned on, the voltage of the positive electrode of the memristor will exceed the positive threshold voltage, thereby causing the resistance of the memristor to decrease; on the contrary, when the NMOS tube Q6 connected to V

[0013] The square wave signal output by the rectifier circuit can be returned to the single-chip microcomputer through a feedback loop, and the single-chip microcomputer can obtain an accurate threshold value by comparing the input signal with the output signal, thereby realizing accurate adjustment and closed-loop monitoring. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a traditional rectifier circuit diagram.

[0015] Figure 2 It is a threshold voltage continuously adjustable flow circuit based on a memristor.

[0016] Figure 3 It is a variation diagram of the resistance of the memristor M1.

[0017] Figure 4 It is a comparison diagram of the output signal and the input signal. DETAILED DESCRIPTION

[0018] In order to make the technical solutions, objectives and advantages of the present application clearer and more explicit, the specific implementation process of the present application will be further described in detail below with reference to the drawings.

[0019] As shown in Figure 2 , the present application proposes a threshold voltage continuously adjustable flow circuit based on a memristor, which comprises a single-chip microcomputer, a rectifier circuit, a memristor control circuit and an upper computer Uart serial communication circuit.

[0020] As shown in Figure 2 , the single-chip microcomputer adopts a 51 series single-chip microcomputer with a Uart function, the GND pin of the single-chip microcomputer is grounded, and the V CCThe pin is connected with 5V voltage source, the P1.0 pin of the single-chip microcomputer is connected with the initial input signal, the P1.1 pin of the single-chip microcomputer is connected with the gate of the NMOS tube Q5, the P1.2 pin of the single-chip microcomputer is connected with the gate of the NMOS tube Q6, the P1.3 pin of the single-chip microcomputer is connected with the gate of the NMOS tube Q7, the P1.5 pin of the single-chip microcomputer is connected with the source of the PMOS tube Q1 and Q3, and the P1.4 pin of the single-chip microcomputer is connected with the output signal of the rectifier circuit.

[0021] As shown in Figure 2 , the rectifier circuit is composed of the memristor M1, the resistor R1, the PMOS tubes Q1 and Q3, and the NMOS tubes Q2 and Q4. The positive pole of the memristor M1 is connected with the input end P1.0, and the negative pole of the memristor M1 is connected with the gates of the PMOS tube Q1 and the NMOS tube Q2. One end of the resistor R1 is connected with the drain of the PMOS tube Q3 and the drain of the NMOS tube Q4, and the other end of the resistor R1 is connected with the gates of the PMOS tube Q1 and the NMOS tube Q2. The drain of Q1 and the drain of Q2 are connected in parallel and serve as the output port of the first stage inverter, and are connected with the gates of Q3 and Q4; the drain of the PMOS tube Q3 and the drain of the NMOS tube Q4 are connected together and serve as the output port of the rectifier circuit; and the sources of the NMOS tubes Q2 and Q4 are grounded.

[0022] As shown in Figure 2 , the memristor control circuit is composed of the positive power supply V CC , the negative power supply V EE , and the NMOS tubes Q5-Q7. The sources of the NMOS tubes Q5 and Q6 are connected with the positive pole of the memristor M1 in parallel, the drains of Q5 and Q6 are connected with the voltage source V CC and the voltage source V EE respectively; the source of the NMOS tube Q7 is grounded, and the drain of Q7 is connected with the negative pole of the memristor M1.

[0023] As shown in Figure 2 , the upper computer and the single-chip microcomputer are connected through the Uart serial port, the upper computer inputs the reference threshold voltage of the rectifier circuit into the single-chip microcomputer, and the single-chip microcomputer calculates the memristor resistance value corresponding to the reference threshold voltage through the internal program.

[0024] In the present application, the forward or reverse threshold voltage of the rectifier circuit is determined by M1, R1 and the power supply of the inverter, and the calculation formula of the forward threshold voltage V ut and the reverse threshold voltage V lt may be respectively expressed as: and .

[0025] In Figure 2The circuit is simulated and verified as an example. The initial resistance of the memristor M1 in the circuit is set to 10 kΩ, the resistance of the resistor R1 is set to 20 kΩ, and the supply voltage of the PMOS tubes Q1 and Q3 in the rectifier circuit is set to 200 mV. The circuit simulation process is as follows: assuming that the rectifier circuit starts to work at 0 ms, then a sinusoidal signal with an amplitude of 100 mV, a frequency of 200 Hz, and a direct current level of 100 mV is input, the supply power of the inverter in the rectifier circuit is disconnected at 25 ms, and the rectifier circuit stops working; then the memristor control circuit starts to work under the control of the single-chip microcomputer, the resistance of the memristor M1 starts to change at 25 ms, the resistance of the memristor M1 stops changing at 36.75 ms, and the supply power of the inverter in the rectifier circuit is restored, and then the rectifier circuit outputs another square wave signal with a different threshold value.

[0026] As shown in Figure 3 , the initial resistance of the memristor M1 is 10 kΩ, which changes from 10 kΩ to 1 kΩ during 25 ms to 36.75 ms, and the resistance of the memristor M1 remains unchanged at other times.

[0027] As shown in Figure 4 , during 0 ms-25 ms, the initial resistance of the memristor M1 does not change, and the rectifier circuit works normally. During this period, by comparing the input sinusoidal wave with the output square wave value, it can be seen that the forward threshold voltage is 150 mV, and the reverse threshold voltage is 50 mV. During 25 ms-36.75 ms, the rectifier circuit stops working and has no output signal, and the memristor control circuit works, and the resistance of the memristor M1 changes. The rectifier circuit starts to work again at 36.75 ms, and the memristor control circuit stops working, and the resistance of the memristor M1 stops changing, and by comparing the input sinusoidal wave with the output square wave value, the forward threshold voltage is 105 mV, and the reverse threshold voltage is 95 mV. It can be seen that before and after the resistance of the memristor M1 changes, the forward threshold voltage and the reverse threshold voltage of the rectifier circuit are consistent with the results calculated by the formula in

[0024] .

Claims

1. A memristor-based threshold voltage continuously adjustable current circuit, characterized in that, It includes single-chip microcomputer, rectifier circuit, memristor control circuit and upper computer Uart serial communication circuit; wherein, the single-chip microcomputer first receives the specific threshold voltage input by the upper computer through the Uart serial port, and calculates the required memristor resistance value by the single-chip microcomputer; secondly, the single-chip microcomputer controls the PMOS tube of the inverter in the rectifier circuit to close its power supply, so that the rectifier circuit stops working; then, the single-chip microcomputer controls the memristor control circuit to work, so that the resistance value of the memristor reaches the preset value, and the single-chip microcomputer controls the memristor control circuit to stop working, so that the resistance value of the memristor is fixed, and at the same time the single-chip microcomputer restores the power supply of the PMOS tube of the inverter in the rectifier circuit, so that the rectifier circuit continues to rectify the input signal; finally, the output signal is returned to the single-chip microcomputer for detection, which is used for closed-loop monitoring of the rectified signal, and realizes more accurate continuous adjustable threshold voltage; The single-chip computer adopts a 51 series single-chip computer with a Uart function, a GND pin of the single-chip computer is grounded, a V CC pin of the single-chip computer is connected with a 5V voltage source, a P1.0 pin of the single-chip computer is connected with an initial input signal, a P1.1 pin of the single-chip computer is connected with a gate of an NMOS tube Q5, a P1.2 pin of the single-chip computer is connected with a gate of an NMOS tube Q6, a P1.3 pin of the single-chip computer is connected with a gate of an NMOS tube Q7, a P1.5 pin of the single-chip computer is connected with sources of PMOS tubes Q1 and Q3, and a P1.4 pin of the single-chip computer is connected with an output signal of a rectifier circuit. The rectifier circuit is composed of a memristor M1, a resistor R1, PMOS tubes Q1 and Q3, and NMOS tubes Q2 and Q4; the positive electrode of the memristor M1 is connected with an input terminal P1.0, the negative electrode of the memristor M1 is connected with the gate electrodes of the PMOS tube Q1 and the NMOS tube Q2; one end of the resistor R1 is connected with the drain electrode of the PMOS tube Q3 and the drain electrode of the NMOS tube Q4, and the other end of the resistor R1 is connected with the gate electrodes of the PMOS tube Q1 and the NMOS tube Q2; the drain electrode of the Q1 and the drain electrode of the Q2 are connected in parallel as the output port of the first stage inverter, and are connected with the gate electrodes of the Q3 and the Q4; the drain electrode of the PMOS tube Q3 and the drain electrode of the NMOS tube Q4 are connected together as the output port of the rectifier circuit; the source electrodes of the NMOS tubes Q2 and Q4 are grounded; The memristor regulation circuit is composed of a positive power supply V CC , a negative power supply V EE , and NMOS tubes Q5-Q7; the sources of the NMOS tubes Q5 and Q6 are connected in parallel with the positive pole of the memristor M1, the drains of Q5 and Q6 are respectively connected with a voltage source V CC and a voltage source V EE ; the source of the NMOS tube Q7 is grounded, and the drain of Q7 is connected with the negative pole of the memristor M1; The upper computer and the single-chip microcomputer are connected through the Uart serial port, the upper computer inputs the reference threshold voltage of the rectifier circuit into the single-chip microcomputer, and the single-chip microcomputer calculates the memristor resistance value corresponding to the reference threshold voltage through the internal program.

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