JPH11251519A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic memory device, in which an LSI which enables stable temperature detection in a temperature detection circuit is provided to a thermal shut down circuit, etc. SOLUTION: An LSI 1 mounted on a magnetic memory device has a large current driver circuit 20 which outputs a current, a temperature detection circuit 23 which detects the temperature due to heat generation of the large current driver circuit 20, signal processing circuit 21 which processes an analog signal for write and read of data to a magnetic memory medium and a controller 22 which controls the large current driver circuit 20 and the signal processing circuit 21. The signal processing circuit 21 is interposed between the temperature detection circuit 23 and the large current driver circuit 20. Since the temperature detection circuit 23 is thereby apart at a distance from the large current driver circuit 20 with the signal processing circuit 21 therebetween and a GND wiring (used in common with an analog circuit) which is not common with a large current driver is used, the temperature detection circuit 23 hardly affects a ground level, etc., even if the large current driver circuit 20 acts to turn on/off, for example.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor device used for a magnetic recording device such as a floppy disk drive.

[0002]

2. Description of the Related Art A conventional magnetic recording apparatus will be described.
FIG. 5 shows an LSI (Large Scal) used in a floppy disk drive, which is a kind of a conventional magnetic recording apparatus.
3 is a diagram showing an arrangement of each circuit in an (e Integrated Circuit) 60. FIG. The LSI 60 includes a large current driver circuit 20 and
It comprises an analog signal processing circuit 21, a controller 22, and a thermal shutdown circuit 23.

A large current driver circuit 20 supplies a current to a stepping motor (not shown) by an on / off operation to drive the stepping motor. The stepping motor is a motor for moving a read / write head (not shown) to a predetermined track position.

An analog signal processing circuit 21 processes an analog signal when writing or reading data to or from a floppy disk as a magnetic recording medium. The controller 22 interfaces with a personal computer (not shown) serving as a host, and controls the large current driver circuit 20 and the analog signal processing circuit 21.

The thermal shutdown circuit 23 has a temperature detection circuit inside, and detects the temperature of the LSI 60 with the temperature detection circuit. Although heat is generated by the operation of the large current driver circuit 20, the thermal shutdown circuit 23 forcibly turns off the large current driver circuit 20 when abnormal heat generation whose temperature exceeds a predetermined reference value occurs. Since the large current driver circuit 20 generates heat by operating, the thermal shutdown circuit 23 prevents the LSI 60 from malfunctioning due to high temperature due to abnormal heat generation. Here, the temperature detection circuit is a circuit shown in FIG. 3 as described later in detail.

[0006]

However, conventionally, the large current driver circuit 20 and the thermal shutdown circuit 23 are provided close to each other as shown in FIG. 5, so that the large current driver circuit 20 and the thermal shutdown circuit 23 are provided as shown in FIG. on/
When the OFF operation is switched, a back electromotive force is generated by a coil of a stepping motor (not shown) connected to the LSI 60, and a current due to the back electromotive force flows to the ground side of the large current driver circuit 20 via the IC substrate. Further, since the current is drawn from the ground side, the ground level VG around the large current driver circuit 20 is set to 0.1 V.
Generates some noise.

For example, at time t1, the large current driver circuit 2
When the operation of “0” is switched from on to off, noise 70 is generated at the ground level VG. At this time, noise 70
As a result, the margin voltage up to the detection voltage VT changes as shown by arrows 71 to 72. As described above, noise is generated when the on / off operation of the large current driver circuit 20 is switched, and the detection voltage changes, so that the temperature detected by the temperature detection circuit changes. Therefore, high-precision temperature detection cannot be performed, and the noise may affect the temperature detection in the thermal shutdown circuit 23.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a magnetic recording apparatus equipped with an LSI capable of detecting a temperature stably in a temperature detection circuit provided in a thermal shutdown circuit or the like. Further, the LSI
Another object of the present invention is to reduce the chip area by devising the arrangement of a thermal shutdown circuit and the like.

[0009]

According to the present invention, there is provided a large current driver circuit for outputting a current, a temperature detection circuit for detecting a temperature due to heat generated by the large current driver circuit, and a magnetic recording device. A semiconductor device comprising: a signal processing circuit for processing an analog signal for writing or reading data to and from a medium (the same applies hereinafter); and a controller for controlling the large current driver circuit and the signal processing circuit. And the large current driver circuit, the signal processing circuit is arranged.

According to such a configuration, the temperature detection circuit provided in the thermal shutdown circuit or the like in the semiconductor device is located at a position separated from the large current driver circuit with the signal processing circuit interposed therebetween, and the GND wiring not shared with the large current driver. (Shared with analog circuit)
The temperature detection circuit hardly affects the ground level and the like even when the large current driver circuit performs, for example, on / off operation. The magnetic recording apparatus drives, for example, a stepping motor by a large current driver circuit. At this time, when the large current driver circuit is operating, no signal reading or writing is performed, so that the signal processing circuit is in a non-operating state. Therefore, even if the signal processing circuit is adjacent to the large current driver circuit, it is not affected by noise generated by the operation of the large current driver circuit.

According to the present invention, in the above configuration, the temperature detection circuit is further arranged at a corner of the LSI. According to such a configuration, LS
Since a temperature detection circuit is provided at the corner of I,
The surface of the LSI can be effectively used. Thus, the area of the LSI chip can be reduced.

[0012]

Embodiments of the present invention will be described below. FIG. 1 is a block diagram of a floppy disk drive device to which the magnetic recording device of the present invention is applied. LS
I1 transmits and receives data to and from a personal computer (hereinafter, referred to as a "PC host") 2 which is a host of a floppy disk drive device, and an interface driver 10 and a controller 12 controls the LSI 1.
Then, the analog signal processing circuit 13 processes an analog signal for writing or reading data to or from a floppy disk (not shown).

The LSI 1 includes an interface driver 10 for transmitting and receiving data to and from the personal computer host 2 and a stepping motor driver 1 for driving the stepping motor 3.
1, an analog signal processing circuit 13, and a controller 12 for controlling these.

The index sensor 5 responds when the disk makes one rotation. Therefore, the controller 12 can determine whether or not there is a disk. The spindle motor 7 is driven by a spindle motor driver 6, and the spindle motor driver 6 is controlled by a controller 12.

The analog signal processing circuit 13 uses the read / write head 9 to write or read data on a floppy disk. Further, the erase head 8 erases a residual portion of unnecessary data on the floppy disk caused by a slight displacement of the track position of the read / write head 9 during a write operation of the read / write head 9.

The track sensor 4 is used to determine the track position of the erase head 8 by mechanically reacting at the position of the track number 0 and to use the track position of the erase head 8 as a reference.

FIG. 2 is a diagram showing an arrangement of each circuit in the LSI 1. The large current driver circuit 20 is a current output unit of the stepping motor driver 11 in FIG. The large current driver circuit 20 is in contact with one side of the LSI 1.
A controller 22 is provided adjacent to the large current driver circuit 20. The controller 22 is a controller. The analog signal processing circuit 2 is located adjacent to the high current driver circuit 20 and the controller 22.
1 is provided.

The thermal shutdown circuit 23
Are provided at corners that are diagonal to the large current driver circuit 20. Therefore, the analog signal processing circuit 21 is arranged between the thermal shutdown circuit 23 and the large current driver circuit 20. The thermal shutdown circuit 23 has the temperature detection circuit shown in FIG. 3, and turns off the large current driver circuit 20 when the detection result indicates that the LSI 1 exceeds a certain reference value.

As shown in FIG. 2, a large current driver circuit 2
0 and the thermal shutdown circuit 23, an analog signal processing circuit 21 is arranged, and GND
Since the lines are not shared, a certain distance is provided. Therefore, noise generated by the ON / OFF operation of the large current driver circuit 20 has almost no influence on the thermal shutdown circuit 23. Also, when the large current driver circuit 20 is turned on / off, the analog signal processing circuit 21 is in a non-operating state, so that the accuracy of the thermal shutdown circuit 23 is not greatly reduced.

FIG. 3 shows a temperature detection circuit in the thermal shutdown circuit 23. The constant current source circuit 30 outputs the constant current I to point A. Then, the constant current I flows from the point A to the ground level via the resistor 32, and at normal temperature, the voltage VT at the point A is kept at about 0.5V. The point A is connected to the base of the NPN transistor 34.
The emitter of the transistor 34 is grounded. Also,
The collector of the transistor 34 is connected to the power supply voltage via the resistor 33, and outputs a signal OUT indicating the temperature detection result from the collector.

Although the resistor 32 and the like have some temperature characteristics,
The point A is kept almost constant even when the temperature of the LSI 1 rises. The NPN transistor 34 is a switching transistor, and a threshold voltage VF between the base and the emitter, which switches on / off, is about 0.7 V at room temperature. When a voltage higher than the threshold voltage VF is applied between the base and the emitter, the NPN transistor 34 turns on.

At normal temperature, the voltage VT at point A is maintained at about 0.5 V, so that the NPN transistor 34 is off. Therefore, the signal OUT becomes high level. Then, when the temperature of the LSI 1 rises, the threshold voltage VF falls, and finally when the temperature drops below the voltage VT at the point A, the transistor 34 turns on, and the signal OUT goes low.

As described above, in the temperature detection circuit, the LSI
1 is detected. Therefore, the signal OUT is at a high level at normal temperature, but is set to a low level at a high temperature of, for example, 150 ° C. or more. Then, when the signal OUT of the temperature detection circuit goes low, the thermal shutdown circuit 23 (see FIG. 2) turns off the large current driver circuit 20 (see FIG. 2).

As shown in FIG. 4, a large current driver circuit 2
0 (see FIG. 2) operates to switch on / off even if the voltage VT of the thermal shutdown circuit 23 is
Almost no noise is generated in both the ground level VG and the ground level VG. Therefore, the high current driver circuit 20 is turned on / off.
Even at the time of switching off, the detection voltage is kept stable as shown by the arrow 40, so that the influence of noise due to the back electromotive force does not occur in the temperature detection.

As described above, in the present embodiment, the analog signal processing circuit 21 is interposed between the large current driver circuit 20 and the thermal shutdown circuit 23 in the LSI 1 used in a floppy disk drive device, etc. Is provided, so that the on / off operation of the large current driver circuit 20 hardly affects the temperature detection in the thermal shutdown circuit 23. Further, the thermal shutdown circuit 23 is an LSI
1, the surface of the LSI 1 can be effectively used, and the chip area can be reduced.

[0026]

As described above, according to the magnetic recording device of the first aspect, in the LSI, the temperature detection circuit is located at a position separated from the large current driver circuit with the signal processing circuit interposed therebetween. Even when the current driver circuit is turned on / off, the ground level and the like of the temperature detection circuit do not vary greatly, and highly accurate and stable temperature detection is possible. Further, when the large current driver circuit is turned on / off, the signal processing circuit is in a non-operating state, so that the accuracy of the thermal shutdown circuit 23 is not affected.

According to the magnetic recording apparatus of the present invention, since the temperature detecting circuit is provided at the corner of the LSI, it greatly contributes to the reduction of the chip area of the LSI, which is a factor of cost reduction.

[Brief description of the drawings]

FIG. 1 is a block diagram of a floppy disk drive device according to an embodiment of the present invention.

FIG. 2 shows the LS of the floppy disk drive.
The figure which shows arrangement | positioning of each circuit in I.

FIG. 3 is a circuit diagram of a temperature detection circuit in the LSI.

FIG. 4 is a waveform chart showing the operation of the LSI.

FIG. 5 shows the L of the conventional floppy disk drive.
The figure which shows arrangement | positioning of each circuit in SI.

FIG. 6 is a waveform chart showing the operation of the LSI.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 LSI 2 PC host 3 Stepping motor 4 Track sensor 5 Index sensor 6 Spindle motor driver 7 Spindle motor 8 Erase head 9 Read / write head 10 Interface driver 11 Stepping motor driver 12 Controller 13 Analog signal processing circuit

Claims (1)

[Claims] A large current driver circuit for outputting a current;
A temperature detection circuit for detecting a temperature caused by heat generated by the high-current driver circuit, a signal processing circuit for processing an analog signal for writing or reading data (hereinafter the same) with respect to a magnetic recording medium; A semiconductor device comprising a controller for controlling a signal processing circuit, wherein the signal processing circuit is disposed between the temperature detection circuit and the large current driver circuit.