JPH0214390A - Electronic circuit device - Google Patents

Abstract

PURPOSE:To appropriately operate the title device as the weight coefficient of each coupling part of a Hopfield circuit by changing a resistance value by the moving of natrium and executing learning by time for impressing the voltage and an ambient temperature. CONSTITUTION:Natrium is previously mixed in the gate insulating film of a MOS FET. When voltage is impressed to a gate electrode, these natrium (+) ions gradually move and concentrate on a lower insulating film after a long time passes. At that time, (-) electrons concentrate at the side of the other P-type substrate. Namely, the same number of the (-) electrons as the number of the (+) ions are to concentrate. Thus, the resistance value becomes smaller, and a large quantity of current is applied between a drain and a source. However, since the natrium (+) ions never move immediately even when voltage is impressed and concentrate with lapse of time the (+) ions move in a way just like a learning operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic circuit device, and more particularly to the configuration of a Hopfield circuit incorporating a variable resistance element.

[Conventional technology]

Recently, a neural network type (neuron network) pattern recognition device has been developed (for example, Nikkei Ellen 1 Heronics, April 18, 1988 (No. 445).
) pp. 106-107). According to the above literature, 3
For a pattern recognition device using a neuron network with a WJ structure, the learning effect is improved by using backpropagation as the basis of the learning algorithm.

By the way, as one of these neuron networks, Hopfield proposed by Hopfield
A dNeuron (Hobfield neuron) circuit is known.

FIG. 5 is a configuration diagram of the Hopfield circuit.

In FIG. 5, μ. ,μ2. ...μ8-0. μ9
are amplifiers, and each amplifier receives an output from a predetermined amplifier via a resistor and one external input, and provides one output to the outside and one output to the inside. For example, the amplifier μ. External human resources X. and amplifier μ8. μ9-0.
and the output from μ9 is input, one internal output and one external output X. ′ is given. One internal output is resistor r. It is connected to an output bus through the output bus, and is inputted from the output bus to a plurality of other amplifiers μ. In that case,
The signals from one amplifier constituting the Hopfield circuit are multiplied by a weighting coefficient via a resistor r and then inputted to the other amplifiers. Now, from amplifier i to amplifier j
Assuming that the weighting coefficient coupled to is tl, this is expressed by the following equation.

jij=ΣXyo8XJB (i≠j)...
(1) □, =O(i=j) ・ ・ ・ ・ (2
) This means that the output from one amplifier is never input to the same amplifier.

Note that 0≦l+J≦N−1.

Input data X to each amplifier μ. - When given XN.

These data are amplified and converted by each amplifier, sequentially transmitted to other amplifiers, and finally output. The actual output turn and the desired output turn (expected value) are compared, and the coupling weight coefficients of each amplifier are changed so as to reduce the difference.

[Problem to be solved by the invention]

A typical learning algorithm for neuron networks is the back propagation method (pack propagation), which sets weights so that the difference between the actual output value and the desired output value when input patterns are given is small. Coefficient) (, 5) (This is a method in which the procedure for changing Jfi is applied sequentially from the output layer to the intermediate layer, and from the intermediate layer to the input layer. By repeating this procedure, the to obtain correct output data.
The weights are converged. This is Hopfield
The same applies to the d circuit.

However, it is necessary to change the weighting coefficient of the coupling part of this amplifier in the same way as human nerves.
Since there is no suitable object in nature, this Hopfiel
There was a problem that the d circuit did not operate well.

The purpose of the present invention is to solve such conventional problems and to operate appropriately as a weighting coefficient of each coupling part of a Hopfiend circuit by incorporating a variable resistor that can give desirable resistance characteristics through learning. The object of the present invention is to provide an electronic circuit device that is capable of

[Means to solve the problem]

To achieve the above object, the electronic circuit device of the present invention inputs outputs from a plurality of amplifiers via different coupling weighting coefficients, receives one external input, and amplifies these input signals. Hopfiel that provides external output as well as output to other amplifiers via coupling weighting coefficients
In the d circuit, sodium is mixed into the gate insulating film of the MOSFET, and a voltage is applied between any two terminals of the gate, drain, and source of the MOSFET, and the resistance value increases due to the movement of the sodium. Hopfiel is a variable resistance element configured to change the voltage, perform learning based on the voltage application time and ambient temperature, and return to the original value as a function of the ambient temperature.
It is used as a weighting coefficient for the coupling part of the d circuit. By making the variable resistance element learn, it is possible to give it a desirable resistance characteristic, and it becomes an element suitable as a weighting factor of the ) Iopfield circuit.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional structural diagram of a variable resistance element showing one embodiment of the present invention.

For example, as shown in Figure 1, a Si P-type substrate (P-3
N-type conductivity is applied to the two locations i) to serve as the source and drain. Next, an insulating film is formed on the silicon, and a large amount of Na+ is contained in the insulating film on the region separating the source and drain. A conductive electrode made of aluminum or the like is deposited on this insulating film by vacuum evaporation or the like.

As a result, a MOS FET having a gate insulating film containing sodium is produced. One N-type portion serves as a source electrode, the other N-type portion serves as a drain electrode, and the metal film on the oxide insulating film serves as a gate electrode.

Since a capacitance is formed between the gate electrode and the P-type substrate by the oxide film, when a positive potential is applied to the gate electrode, holes, which are majority carriers in the P-type, are kept away from the part under the oxide film. , free electrons, which are minority carriers, gather.

In this example, sodium is mixed, and when voltage is applied to the gate electrode, these sodium (+
) The ions gradually move and collect on the lower insulating film after a long period of time. At this time, (-) electrons are concentrated on the other P-type substrate side. In other words, the same number of (-) electrons as the number of (+) ions will gather. This reduces the resistance value and allows a large amount of current to flow between the drain and source. However, even when a voltage is applied, the sodium (+) ions do not move immediately, but rather gather as time passes, so the movement is similar to a learning operation.

FIG. 2(a) is an equivalent circuit of FIG. 1, in which a voltage of 5V is applied between the gate electrode G and the source electrode S.

FIG. 2(b) shows the voltage of the variable resistance element in FIG. ! !
It is a flow characteristic diagram.

As the voltage applied between the drain and source increases, the current between the drain and source increases to a certain extent, but even if a voltage higher than that is applied, the current value saturates. Now, considering the resistance value, which is the slope of this characteristic curve, this resistance value changes depending on the movement of sodium, so (a) it changes depending on the applied voltage value. (b) Varies depending on the time the voltage is applied. (c) Varies depending on the ambient temperature. (It has the function of memory. (E)
It has the characteristic of performing learning movements.

That is, when a high voltage is applied, the resistance value decreases.

The longer a voltage is applied, the lower the resistance is maintained without returning to its original state even after the voltage application is stopped. For a short time? ! ! After applying pressure,
When the application is stopped, the resistance returns to high immediately. Furthermore, if no voltage is applied for a long time, the memory will be forgotten. In other words,
It returns to high resistance. Next, as the temperature increases, the resistance value changes quickly. Also, the higher the temperature, the faster it will return to its original state.

Furthermore, if the number of times of application is increased, it will not return to 1. In other words, it becomes difficult to forget.

The above can be summarized as follows.

(i) The learning time is a function of the voltage application time and the ambient temperature. (ii) The recovery time is a function of ambient temperature.

Therefore, if the variable resistance element of this embodiment is used as a weighting coefficient of a coupling part of a Hopfield circuit, it will become an extremely suitable electronic circuit device because it operates in a manner similar to the human nervous system.

FIG. 3 is a circuit diagram of a main part when a variable resistance element according to the present invention is built into the Hopdield circuit of FIG.

1 to 6 constitute one amplifier μ, 7°8 is a variable resistance element that provides a weighting coefficient, and 9 to 14 are the other 1.
It consists of two amplifiers μ. 1 and 9 are amplifier circuits on the positive polarity side, 2 and 10 are amplifier circuits on the negative polarity side, and 3 to 9 are amplifier circuits on the positive polarity side;
6 and 11 to 14 are resistors in the amplifier circuit, 7 is a P-channel MOSFET that is a variable resistance element that changes to the positive polarity side, and 8
is the N-channel MO5 of the variable resistance element that changes to the negative polarity side.
It is an FET. In FIG. 5, one amplifier μ. Outputs from a plurality of amplifiers .mu., . That is, the input terminals of amplifiers 9 and 10 in FIG.

Although a plurality of inputs are coupled via other variable resistance elements, in order to simplify the configuration, only one input is provided here via only one set of variable resistance elements 7 and 8.

The variable resistance elements 7 and 8 supply signals to the next stage amplifier circuits 9 and 10 using x and "xJs as coupling weighting coefficients, and also supply signals having the same weighting coefficients to other amplifiers. .

FIG. 4 is a voltage-current characteristic diagram of the variable resistance element in FIG. 3.6 FIG. (b) is a characteristic curve of drain-source current versus drain-source voltage of an N-channel MO9FET.

When the voltage increases for the same voltage, the P-channel MO5
In the FET, the current increases as indicated by the arrow, whereas in the N-channel MOSFET, the current decreases as indicated by the arrow. In this way, by raising one of a set of MOS FETs and lowering the other, control in the opposite direction can be performed.

〔Effect of the invention〕

As explained above, according to the present invention, desired resistance characteristics can be given by training the variable resistance element, and by using this as a weighting coefficient of the coupling part of the Hopfield circuit.

It is possible to make it perform actions similar to human nerves.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional structural diagram of a variable resistance element showing an embodiment of the present invention, Fig. 2 is an equivalent circuit diagram and characteristic diagram of Fig. 1, and Fig. 3 is a Hopfield circuit of the variable resistance element of Fig. 1. Main part configuration diagram when built-in, Figure 4 is one set of MOS in Figure 3
The characteristic diagram of the FET, FIG. 5, is a configuration diagram of a conventional Hopfield circuit. 1.2, 9, 10: amplifier circuit, 3-6, 11-14: resistor, 7, 8: variable resistance element of the modified invention. Patent applicant Riko Co., Ltd. -1 Noji:, - and [=.

Claims (2)

[Claims] (1) Input the outputs from multiple amplifiers via different coupling weighting coefficients, receive one external input, amplify these input signals, and output them to other amplifiers via the coupling weighting coefficients. Hop that provides external output
In the field circuit, as the weighting coefficient, MOS
Sodium is mixed into the gate insulating film of the FET,
An electronic circuit device characterized by using a variable resistance element that changes the resistance value by the movement of sodium by applying a voltage between the gate and drain terminals, between the gate and source terminals, or between the gate substrate terminals of the MOSFET. . (2) The above variable resistance element uses a pair of P-channel MOSFET and N-channel MOSFET, and performs learning based on the application time of the voltage applied between the terminals of the FET and changes in the ambient temperature. 2. The electronic circuit device according to claim 1, wherein the original resistance characteristic is restored by a function.