JPS6240786A - Magnetic coupling isolator using magnetic reluctance element - Google Patents

Abstract

PURPOSE:To manufacture an magnetic coupling isolator small in size and low in production cost, and to improve its high frequency characteristics, by composing it of an input conductor pattern and an output magnetic reluctance element. CONSTITUTION:An input conductor pattern 1 using a thin film conductor, and an output magnetic reluctance element 3 formed through an insulating film 2 on the pattern 1 are provided. A magnetic field change in response to the variation in the input current of the pattern 1 is detected by the element 3, and its signal is output as a voltage change. Thus, the function as a magnetic coupling isolator can be performed.

Description

[Detailed Description of the Invention] [Summary] A magnetic coupling isolator using a magnetoresistive element, which electrically isolates input and output by using a method in which the magnetic field generated by a conductive pattern is detected by the magnetoresistive element, and Signal transmission can be performed at high speed, and the device can be made into a solid-state device.

[Industrial application field]

The present invention relates to a magnetically coupled isolator using a magnetoresistive element.

[Conventional technology]

To form an isolator, signals must be transmitted while being electrically isolated in some way. Conventionally, magnetic fields or light have been used for signal transmission.

[Problem that the invention seeks to solve]

Relatively small transformer-coupled isolators that utilize magnetic fields have been put into practical use, but they are somewhat large and have a limited wavenumber characteristic (~30 KHz). In addition, photocoupler type isolators that use light are small and have a high speed (up to MHz) that have been put into practical use, but they have the drawback of being rather expensive.

The present invention was created in view of these points, and an object of the present invention is to provide an isolator that uses a conductive pattern and a magnetoresistive element, has good frequency characteristics, and can be manufactured inexpensively and compactly.

Means for Solving Problem C] Therefore, in the present invention, the input conductor pattern 1 using a thin film conductor and the BbF! Insulating film 2 on + body pattern 1
It is characterized in that it consists of an output magnetoresistive element 3 provided via an output magnetoresistive element 3.

[For production]

By detecting changes in the magnetic field in accordance with changes in the input current of the conductor pattern 1 with the magnetoresistive element 3 and outputting the signal as a voltage change, it is possible to function as a magnetic coupling isolator.

〔Example〕

FIG. 1 is a diagram showing an embodiment of the present invention, in which a is a plan view and b is a cross-sectional view taken along line bb'-b# of diagram a.

In this embodiment, as shown in FIGS. 1a and 1b, a conductor pattern 1 made of a conductor and a magnetoresistive element 3 (the part surrounded by the two-dot chain line) are connected to the conductor pattern with an insulating layer 2 interposed therebetween. It is provided on the substrate 4. The substrate 4 is made of glass or Si, and the conductor pattern is made of metal such as Au.
The insulating layer 2 is made of SiO□, which has a high dielectric breakdown voltage.

Further, the magnetoresistive element 3 is of a barber pole type. This barber pole type magnetoresistive element 3 has a thickness of 50 mm.
0 to 1000 people, 1 pair 5 and 6 of a zigzag pattern using a soft magnetic thin film such as permalloy with a width of 8 μm are formed symmetrically, and one end of each is used for drawing out through a through hole 7.8. The conductor pattern 9.10 is connected to the conductor pattern 9.10, and each other end thereof is connected to the same drawer thin pattern 12 through the through hole 11, and on the meander-like pattern 5.6 there is a pattern as shown in FIG. The conductor pattern 13 is formed with a diagonal of 45'' on pattern 5 and a width of 2.8 pm with a width of 2.8 pm and a width of 2.11 Im on pattern 6.

In this embodiment configured in this way, the zigzag patterns 5 and 6 are connected to the variable resistor 14 as shown in the circuit diagram of FIG.
The DC voltage component is equal across v. ■ DC power supply in parallel so that. , and the conductor patterns 9 and 10 are connected to the differential amplifier 15. If an input current l is applied to the conductor pattern l shown in FIG. As shown in FIG. 4, output voltages VL and V whose phases are different by 180° are generated. If the dimensions of the zigzag patterns 5 and 6 are made the same, the output voltages ■ and ■6 will be equal, and if they are amplified by the differential amplifier 15, the output voltages ■ and ■6 will be equal. are canceled out, and only the changes ΔVL and ΔvR are emphasized to obtain approximately 2×ΔvL.

If the direction of the current (2) flowing through the conductor pattern 1 and the longitudinal direction (direction of easy magnetization depending on the shape) of the zigzag pattern 5.6 of the magnetoresistive element 3 are arranged so as to be parallel to each other as shown in FIG. The outputs ΔV1 and Δ■ are maximum. Note that it is desirable that the width of the conductive pattern 1 be 120% or more of the area S of the entire element (shown in FIG. 1) in order to obtain a uniform magnetic field.

In addition, the size of this implementation is approximately 5008 m x 500 μm, and when fabricating this as a device, it can be further miniaturized by forming a transistor for input current generation, a transistor for differentially amplifying the output, etc. on the same chip. be able to. In addition, the characteristics are input current ±20m
When A, an output of approximately 10 mV is obtained, and the limit frequency is approximately 1
Possible up to 0MH2.

〔Effect of the invention〕

As described above, according to the present invention, the configuration consisting of the input conductor pattern and the output magnetoresistive element is small,
It can be manufactured at low cost and has good high frequency characteristics, making it extremely useful in practice.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is an enlarged view showing a part of the magnetoresistive element, FIG. 3 is a circuit diagram using the embodiment of the present invention, and FIG. 4 is a diagram showing an embodiment of the present invention. It is a figure which shows the input and output waveform of an Example. 1, 2, and 3, 1 is an input conductor pattern, 2 is an insulating layer, 3 is a magnetoresistive element, 4 is a substrate, 5.6 is a meandering pattern, and 7.8.11 is a through hole. 9.10.12 is a lead-out conductor pattern; 13 is a conductor pattern on the serpentine pattern; 14 is a variable resistor; and 15 is a differential amplifier. Figures showing embodiments of the present invention Figure 1 Figure 3 Magnetoresistive sensor 4 Enlarged diagram showing substrate 9, IO, +2-'-drawing conductor Figure 2 13 Conductor pattern of the present invention Figure 3 showing the circuit using the embodiment 5.6...Meander-shaped E-turn 14...Variable resistor 15...Differential amplifier Figure 4 showing the input and output waveforms of the embodiment of the present invention figure

Claims (2)

[Claims] 1. A magnetic device characterized by comprising an input conductor pattern (1) using a thin film conductor, and an output magnetoresistive element (3) provided on the conductor pattern (1) via an insulating film (2). Magnetic coupling isolator using resistive elements. 2. A barber pole type magnetoresistive element is used as the magnetoresistive element (3), and the element is arranged so that its direction of easy magnetization is parallel to the direction of current flow in the conductor pattern (1). A magnetic coupling isolator using the magnetoresistive element according to claim 1.