JPS58139390A - Magnetic bubble drive circuit - Google Patents

Abstract

PURPOSE:To improve the reliability against the operating temperature change, by connecting an external resistor matching the resistance temperature coefficient of each conductor and a current temperature coefficient of magnetic bubbles in series with each conductor of bubble memories and driving the memories with a constant voltage source. CONSTITUTION:In a drive circuit of a function conductor R14 such as magnetic bubble generator and bubble expander, a current correction resistor R23 is connected in series with the conductor R14. The current flowing to the R14 is kept to a current value optimizingly initially set even with the resistance change. The bubbles, however, have the current temperature coefficient in which the required current is reduced according to the temperature rise of the magnetic substance film, the current correction resistor connected in series corrects the current so as to drive the bubbles at the required optimum current for the bubbles. Thus, the suitable current is applied to each conductor according to the temperature of the magnetic substance film, allowing avoid malfunction.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a drive circuit for a two-layer conductor current-driven magnetic bubble memory with improved reliability against changes in operating temperature.

(Background Art) Two methods of transferring magnetic bubbles are the field access type, in which a permalloy pattern on a magnetic film is used as a transfer path, and the rotating magnetic fields of X and Y coils are used to transfer magnetic bubbles, and the first conductor layer is stacked on the magnetic film in an insulated manner. There is also a two-layer conductor current driven type in which patterned holes are provided in the second conductive layer and a magnetic bubble is transferred by a magnetic gradient created in the patterned holes by passing a current through each conductive layer at appropriate times. For details on the principles behind the present invention, please refer to the literature (The BellS
system Technical Journal Vo
158 Nth61978 ) in detail 0 FIG. 1 is a diagram showing the principle pattern layout of a two-layer conductor current-driven magnetic bubble memory. In FIG. 1, l is the first conductor layer,
2 is a second conductor layer, 3 is a generator, 4 is a magnetic bubble expander,
5 and 5' are detectors, 6 is a swap gate, 7 is a replicate gate, and 83 to 8n are minor loops (storage parts). Further, each arrow indicates a transfer path of the magnetic bubble and indicates the direction of movement of the magnetic bubble. The transfer of magnetic bubbles is performed by applying current to the first conductor layer 1 and the second conductor layer 2 at appropriate times, and other functions such as generation of magnetic bubbles are performed by a generator 3 and detection by a magnetic bubble expander 4 at appropriate times. This is done by controlling magnetic bubbles by applying an electric current. Hereinafter, the first conductor layer 1 and the second conductor layer will be simply referred to as a conductor, the others will be collectively referred to as a functional conductor, and the magnetic bubble will be referred to as a bubble.

FIG. 2 is an example of a conventional functional conductor drive circuit.

In Figure 2, 11 is an inverter buffer, R11, R1
2 is a current setting resistor, R13 is a current detection resistor, QIO is a transistor, and R14 is a functional conductor.

The operation of the circuit is schematically represented by an input signal being applied to terminal 10. (VCE (11 is inverter buffer 1
1, the base-emitter voltage of the transistor QIO in BB10, VCC is the power supply voltage, and l is the current flowing through the functional conductor R14).

In other words, the current 1 flowing through the functional conductor R14 is
Regardless of the resistance value of the current setting resistor R11゜R12
, is determined by the current detection resistor R13.

When the current i is initially set to a current value suitable for each of the functional conductors R14 (generator 3, bubble expander 4, etc.), the current value remains at the initial setting even if the resistance value of the functional conductor R14 changes thereafter. It is maintained. However, the current required to operate the bubble decreases as the temperature of the magnetic film rises, approximately -0.2
It has a current temperature coefficient of %/'C, and if the current at 0°C is 1.0, the appropriate current value is 0.8 at 100°C. However, in conventional drive circuits, even if the temperature of the magnetic film changes and the resistance value of the conductor or functional conductor that is in close contact with the magnetic film changes, the current value remains constant. If the initial setting is made to a current value of 100°C, the current value of 20° will be excessive, and if the initial setting is made to the current value of 100°C, 20% of the current value will be unstable at 0°C, and the current will be If it is excessive, it increases the temperature rise, causes bubbles to occur in unnecessary areas, and causes malfunction, and if it is unstable, it becomes impossible to operate.

(Problems to be solved by the invention) The purpose of the present invention is to supply an appropriate current to a conductor and a functional conductor according to the temperature of the magnetic film in order to eliminate these drawbacks. A thin magnetic film is formed on top, and a first conductor layer and a second conductor layer are stacked on top of each other insulated from each other, and a major transfer path and a minor transfer path are formed by the turn holes provided in each conductor layer. A magnetic bubble input/output control function that constitutes a circuit and is insulated and overlapped with the first conductor layer and the second conductor layer (a two-layer conductor current drive having means for applying a bias magnetic field in the thickness direction of the turn layer and the magnetic film) In the drive circuit of the type magnetic pull device,
An external resistor that matches the resistance temperature coefficient of the first conductor layer, the second conductor layer, and the magnetic bubble input/output control function pattern layer with the current temperature coefficient of the magnetic bubble is connected in series with each conductor, and the series circuit is It is a magnetic bubble drive circuit that is driven by a constant voltage source.

(Structure and operation of the invention) FIG. 3 shows a first embodiment of the invention, in which 21 is a buffer, R21 and R22 are current detection resistors, Q20 is a transistor, R23 is a current correction resistor, and R14 is a functional conductor. .

The operation of this circuit is that when an input signal is applied to the terminal, a voltage of approximately 21 ■E'' R21 + R22°VCC is output to the emitter of the transistor Q20, and a voltage of approximately 21 ■E'' R21 + R22°VCC is output to the functional conductor R14 via the current correction resistor 1 (B). A current is supplied.

The current correction resistor R23 is determined by the following equation, and is used to obtain the optimum current for always operating the bubble even if the temperature of the magnetic film changes.

Now, if the operating temperature of the bubble is 1-1 from 0°C to 100°C, the following equation holds true.

1(0):VE/(R(o)10R23)iCloo)=
■E 4R (100) + R23) 100°” ””
'(0) '(too)/tortoise(.)'(0
) Optimal current value of functional conductor R14 at 20°C, '(
too) = optimum current value of functional conductor R14 at 100°C, R(.) = resistance value of functional conductor R14 at 0°C,
”(loo) = resistance value of functional conductor R14 at 100°C, ■. = emitter voltage of transistor Q20, α - current temperature coefficient of bubble, current temperature coefficient of bubble -0.2%/°C, functional conductor R14
If the temperature coefficient of resistance is -0.34%/'C, the optimum value of the current correction resistance) t23 is 36% of the resistance R(.) of the functional conductor R14 at 0°C. Here, correction resistor R23
The value of is determined by two-point approximation so that the current value is optimal at the upper and lower limits of the operating temperature, but the deviation from the optimal value at each temperature is greatest in the middle of the temperature range. However, the value is 1.2%
This is the following and does not pose a practical problem.

Although the above description has been about the functional conductor, the same thing can be said about the driving of the first conductor layer and the second conductor layer.

As explained above, by simply inserting one selected resistor in series with each functional conductor, it is possible to always supply the optimum current for bubble operation, so the current is unstable due to temperature changes in the magnetic film. , and the resulting malfunctions can be prevented, and by suppressing excessive current, power consumption can be reduced, heat generation can be suppressed, and bubble memory packaging can be miniaturized.

(Effects of the Invention) The present invention uses a current correction resistor to always drive the bubble with the optimum current necessary for bubble operation, making it possible to realize a highly reliable magnetic bubble memory that generates less heat and has fewer malfunctions. ,ECR.

It can be used as memory for PO8 terminals, etc.

[Brief explanation of the drawing]

Fig. 1 is a diagram of the principle pattern layout of a two-layer conductor current-driven magnetic bubble memory, Fig. 2 is a conventional functional conductor drive circuit diagram, and Fig. 3 is a functional conductor drive circuit diagram of an embodiment of the present invention. be. 21 is a buffer, l't21. R22 is a tortoise, pressure setting piece resistor, Q20 is a transistor, R23 is a current correction resistor,
R14 is a functional conductor. , Patent applicant Oki Electric Industry Co., Ltd. Patent application agent Patent attorney Megumi Yamamoto - Figure 1

Claims (1)

[Claims] A thin magnetic film is formed on a non-magnetic garnet substrate, and a first conductor layer and a second conductor layer are stacked on top of each other insulated from each other, and patterned holes provided in each conductor layer provide a major transfer path and a minor transfer path. A transfer path is formed by forming a first conductor layer and a second conductor layer.
In a drive circuit for a two-layer conductor current-driven magnetic bubble device, which has a magnetic bubble input/output control function pattern layer that is insulated and overlapped with the conductor layer, and means for applying a bias magnetic field in the thickness direction of the magnetic film, the first conductor layer, the first Match the resistance temperature coefficient of the two conductor layers and the magnetic bubble input/output control function pattern layer with the current temperature coefficient of the magnetic bubble. A magnetic bubble drive circuit characterized in that an external resistor is connected in series with each conductor, and the series circuit is driven by a constant voltage source.