JPH04109458A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To realize low power consumption without taking an counter-measure against a switching noise by controlling the revolving speed of a spindle motor by an analog system at the time of read operation, and controlling the revolving speed of the spindle motor by a pulse width modulation system at the time of non-read operation. CONSTITUTION:In the case that a read gate signal designates the read operation, a control signal from an analog system control circuit 2 is switched by a control signal switching circuit 4, and is outputted to a spindle motor drive circuit 5, and in the case that the read gate signal designates the non-read operation, the control signal from a PWM system control circuit 1 is switched by the control signal switching circuit 4, and is outputted to the spindle motor drive circuit 5. Accordingly, since the spindle motor drive circuit 5 drives the spindle motor by the control signal from the analog system control circuit 2 to generate a few noise at the time of the read operation, it has a high read margin, and simultaneously, it drives the spindle motor by the control signal from the PWM system control circuit 1 to have a little power loss at the time of the non-read operation. Thus, the low power consumption can be realized.

Description

TECHNICAL FIELD The present invention relates to a magnetic disk drive, and more particularly to read operation control and spindle motor rotational speed control in a magnetic disk drive.

Prior Art Conventionally, in magnetic disk devices, the rotational speed of the spindle motor has been controlled independently of the REET operation, and in devices with a PWM (pulse width modulation) control circuit, the spindle The rotational speed of the motor is controlled, and in devices having an analog control type control circuit, the rotational speed of the spindle motor is controlled using an analog control type.

In such conventional magnetic disk drives, when the rotational speed of the spindle motor is controlled using the PWM control method,
Although there is an advantage that the power loss in the spindle motor drive circuit is small, there is a disadvantage that a lot of noise is generated during the switching operation of the circuit, and it is necessary to take countermeasures against switching noise.

Furthermore, when the rotational speed of the spindle motor is controlled using an analog control method, although it has the advantage of generating less noise, it also has the disadvantage of large power loss in the spindle motor drive circuit.

Purpose of the Invention The present invention has been made to eliminate the drawbacks of the conventional devices as described above, and an object of the present invention is to provide a magnetic disk device that can achieve low power consumption without taking measures against switching noise. .

Structure of the Invention A magnetic disk device according to the present invention is a magnetic disk device that rotationally drives a magnetic disk medium by a spindle motor, and includes a first control means that controls the rotation of the spindle motor using a pulse width modulation method, and an analog method. a second control means for controlling the rotation of the spindle motor;
Selecting a control signal from the second control means when a read/write instruction signal for the magnetic disk medium is input, and controlling from the first control means when the read/write instruction signal is not input. The present invention is characterized in that it includes a selection means for selecting a signal.

Embodiment Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In the figure, a PWM (Pulse Width Modulation) type spindle motor rotation speed control circuit (hereinafter referred to as PWM type control circuit) 1 compares a triangular wave signal generated by a triangular wave generation circuit (not shown) with a current setting amount to be driven. An on/off signal is generated based on the comparison result, and the spindle motor drive circuit 5 is controlled on/off using the on/off signal.

Analog type spindle motor rotation speed control circuit (hereinafter referred to as analog type control circuit) 2 is INDEX To
INDEX interval and set rotation speed Teno ideal INDEX T
The time difference with the OINDEX interval is used as an error signal, and a drive current proportional to the error is passed through the spindle motor (not shown) to control the rotational speed of the spindle motor.

A read/write sequence control circuit (hereinafter referred to as a sequence control circuit) 3 generates a read/write signal that specifies a read operation and a non-read operation to control reading and writing to a magnetic disk medium (not shown). The data is output to a write/read controller (not shown) of the disk medium.

The control signal switching circuit 4 switches the control signal from the PWM type control circuit 1 and the control signal from the analog type control circuit 2 in response to the gate signal from the sequence control circuit 3 and outputs it to the spindle motor drive circuit 5. do.

That is, when the read gate signal specifies a read operation, the control signal from the analog control circuit 2 is switched by the control signal switching circuit 4 and output to the spindle motor drive circuit 5, and the read gate signal specifies a non-read operation. When specifying an operation, the control signal from the PWM control circuit 1 is switched by the control signal switching circuit 4 and output to the spindle motor drive circuit 5.

As a result, the spindle motor drive circuit 5 drives the spindle motor using the control signal from the analog control circuit 2, which generates less noise during read operations, so it has a high read margin and uses the PWM method, which has less power loss during non-read operations. Since the spindle motor is driven by the control signal from the control circuit 1, a low consumption horn can be realized.

Here, in the write operation, position information is read from the magnetic disk medium and then data is written, so the spindle motor drive circuit 5 drives the spindle motor by the control signal from the analog control circuit 2, as in the read operation. I will do it.

In this way, the spindle motor is driven by the control signal from the analog control circuit 2 that generates less noise during read operations, and PWM with less power loss during non-read operations.
By driving the spindle motor with a control signal from the system control circuit 1, a high read margin can be achieved during read operations, and low power consumption can be achieved during non-read operations.

Therefore, low power consumption can be achieved without taking measures against switching noise.

Effects of the Invention As explained above, according to the present invention, the rotational speed of the spindle motor is controlled using an analog method during lead operation, and the rotation speed of the spindle motor is controlled using a pulse width modulation method during non-lead operation. This has the effect of making it possible to reduce power consumption without having to take measures against switching noise.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. Explanation of symbols of main parts 1...PWM spindle motor rotation speed control circuit 2...Analog spindle motor rotation speed control circuit 3...Read/write sequence control circuit 4...
・Control signal switching circuit

Claims (1)

[Claims] (1) A magnetic disk device that rotationally drives a magnetic disk medium by a spindle motor, which includes a first control means that controls the rotation of the spindle motor using a pulse width modulation method, and a first control means that controls the rotation of the spindle motor using an analog method. a second control means for controlling the magnetic disk medium when an instruction signal for reading and writing to the magnetic disk medium is input;
A magnetic disk drive comprising: a selection means for selecting a control signal from the first control means, and selecting a control signal from the first control means when the read/write instruction signal is not input.