JP2006166666A - Motor driving semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor driving semiconductor device for restricting an increase of temperature without depending on outer control before its internal temperature attains a temperature where thermal breakdown is caused, namely a temperature where a motor drive current should be shut down. <P>SOLUTION: When detecting a prescribed fixed temperature T1 lower than a temperature T2 where a motor drive current should be shut down, a temperature detecting circuit 1 generates a temperature detection signal 11. While the temperature detection signal 11 is entered, a motor drive transistor controlling circuit 5 controls a motor drive transistor circuit 2 so that a motor drive current is generated which is limited at a prescribed ceiling value, and thereby a current value of the motor drive current is held down low. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a motor driving semiconductor device that controls driving of a motor.

  For example, in a semiconductor device for motor drive that controls the drive of an optical disk rotation motor of an optical disk device, as a countermeasure against heat generation, when a predetermined constant temperature before thermal destruction occurs is detected, the motor drive current is shut down and lowered to a certain temperature. By the way, it was made to return to a drive state (for example, refer patent document 1). As another heat generation countermeasure, if a predetermined constant temperature lower than the temperature before the thermal breakdown occurs, that is, the temperature at which the motor drive current must be shut down is detected, a warning signal is output to the outside of the semiconductor device to the user. A warning can be made so that the user can take necessary measures before the motor drive current is shut down (see, for example, Patent Document 2).

  However, in recent years, the optical disk apparatus has been increased in speed and the amount of heat generation has become very large. Therefore, there is a problem that the shutdown frequently occurs only by detecting a predetermined constant temperature and shutting down the motor drive current. That is, when the motor drive current is shut down, the motor control is completely disabled during the period until the temperature is lowered. Therefore, if the shutdown frequently occurs, the recording or reproducing operation of the optical disk is hindered.

  In addition, heat generation countermeasures that allow the user to take the necessary measures allow the user to take the necessary measures before shutting down and prevent the motor drive current from shutting down, but it takes time for the user. It was a thing.

On the other hand, in recent years, multi-functionalization using a large number of external connection pins is also progressing in motor drive semiconductor devices, and therefore there is a demand for securing external connection pins as much as possible. In order to take measures, the heat generation countermeasure requires an external connection pin for outputting a warning signal, which is against the demand for multi-functionality.
Japanese Patent Application Laid-Open No. 6-121452 JP 2000-184581 A

  In view of the above problems, the present invention, when detecting a predetermined constant temperature lower than the temperature at which the motor drive current before the thermal destruction must be shut down, limits the motor drive current by a predetermined upper limit value, An object of the present invention is to provide a semiconductor device for motor drive that can suppress a temperature rise without relying on external control before reaching a temperature at which the motor drive current must be shut down by suppressing the current value of the motor drive current. And

  According to a first aspect of the present invention, there is provided a motor driving semiconductor device comprising: a motor driving current generating means for generating a motor driving current for defining a rotating operation and a braking operation of the motor to drive the motor; and a detected temperature of a predetermined constant temperature. A temperature detection signal that outputs a temperature detection signal when the temperature exceeds the predetermined constant temperature, or a temperature detection unit that stops outputting the temperature detection signal when the detection temperature falls below a predetermined value from the predetermined constant temperature; and the motor drive A motor driving current detecting means for detecting a motor driving current generated by the current generating means; and the motor driving so as to generate a motor driving current limited by a predetermined upper limit value while the temperature detection signal is output. And a control means for controlling the current generation means.

  The motor drive semiconductor device according to claim 2 of the present invention is the motor drive semiconductor device according to claim 1, wherein the motor drive current detection means detects a motor drive current generated by the motor drive current generation means. A voltage corresponding to the current value, and the control means takes a difference between an external torque command voltage and a voltage from the motor drive current detection means to generate a torque command voltage, and the temperature A torque limiter that limits and outputs a torque command voltage with a predetermined limit value while the detection signal is being output, and a motor that controls the motor drive current generation means based on the torque command voltage from the torque limiter A drive control circuit, and limiting the torque command voltage from the torque command voltage generation circuit with a predetermined limit value while the temperature detection signal is being output. Motor drive current limited by a predetermined upper limit value, characterized in that to be regenerated.

  The semiconductor device for motor drive according to claim 3 of the present invention is the semiconductor device for motor drive according to claim 2, wherein the control means receives the short brake command or the reverse brake command as an external brake command. A short brake control command signal or a reverse brake control command signal is output to the motor drive control circuit according to the external brake command while the temperature detection signal is not output, and a short circuit occurs while the temperature detection signal is output. A brake control circuit is provided for outputting a brake control command signal to the motor drive control circuit. The motor drive control circuit responds to a command signal when a short brake control command signal or a reverse brake control command signal is input. Controlling the motor driving current generating means so as to generate a motor driving current. A function, characterized in that.

  According to a fourth aspect of the present invention, there is provided a semiconductor device for driving a motor, the motor driving current generating means for driving the motor by generating a motor driving current for defining the rotational operation and the brake operation of the motor, and the detected temperature being a first constant. When the temperature is higher than the first temperature, the first temperature detection signal is output. When the temperature is higher than the second temperature higher than the first temperature, the second temperature detection signal is output. When the detection temperature is lower than the second constant temperature, Alternatively, when the constant temperature decreases from the second constant temperature, the output of the second temperature detection signal is stopped, and when the detected temperature falls below the first constant temperature, or the constant value decreases from the first constant temperature. Then, temperature detection means for stopping the output of the first temperature detection signal, motor drive current detection means for detecting the motor drive current generated by the motor drive current generation means, and the first temperature detection signal are output. The motor driving current generating means is controlled to generate a motor driving current limited by a predetermined upper limit value while the second temperature detection signal is being output. Control means for controlling the motor drive current generation means so that the motor drive current is not generated by the current generation means.

  The motor drive semiconductor device according to claim 5 of the present invention is the motor drive semiconductor device according to claim 4, wherein the motor drive current detection means detects a motor drive current generated by the motor drive current generation means. A voltage corresponding to the current value, and the control means generates a torque command voltage by taking a difference between an external torque command voltage and a voltage from the motor drive current detecting means, and the first A torque limiter that limits and outputs a torque command voltage with a predetermined limit value while the temperature detection signal 1 is output; and the torque limiter when the second temperature detection signal is not output. The motor drive current generating means is controlled based on the torque command voltage from the motor, and while the second temperature detection signal is being output, the motor drive current generating means generates a motor drive current. A motor drive control circuit for controlling the motor drive current generation means so as not to generate the torque command voltage from the torque command voltage generation circuit while the first temperature detection signal is being output. The motor drive current limited by a predetermined upper limit value is generated by limiting with the limit value, and while the second temperature detection signal is being output, the motor drive current generating means outputs a motor. It is characterized in that no drive current is generated.

  The semiconductor device for motor drive according to claim 6 of the present invention is the semiconductor device for motor drive according to claim 5, wherein the control means receives the short brake command or the reverse brake command as an external brake command. While the first temperature detection signal is not output, a short brake control command signal or a reverse brake control command signal is output to the motor drive control circuit according to the external brake command, and the first temperature detection signal is output. A brake control circuit that outputs a short brake control command signal to the motor drive control circuit while the motor drive control circuit is being operated. The motor drive control circuit receives a short brake control command signal or a reverse brake control command signal. And a motor corresponding to the command signal while the second temperature detection signal is not output. A function of controlling the motor driving current generating means to generate a dynamic current, characterized in that.

  According to the present invention, it is possible to suppress heat generation while continuing to drive the motor, and avoid a motor control disabled state due to shutdown of the motor drive current. Further, since control for suppressing heat generation is performed inside the motor drive semiconductor device, it is not necessary to prepare an external connection pin for outputting a warning signal to the outside, and the external connection pin can be used for other functions. Further, it is not necessary for the user to take necessary measures, and the user's trouble can be saved.

Hereinafter, a motor driving semiconductor device according to an embodiment of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 is a schematic block diagram of a motor driving semiconductor device according to the first embodiment.

  In FIG. 1, reference numeral 1 denotes a temperature detection circuit as an internal temperature detection means. The temperature detection circuit 1 detects the internal temperature of the motor driving semiconductor device. When the motor driving semiconductor device generates heat and the internal temperature rises to a temperature T1 or higher, the first temperature detection signal 11 is output. When the temperature rises to a temperature T2 or higher, the second temperature detection signal 12 is output. Is output. Further, the temperature detection circuit 1 stops the output of the second temperature detection signal 12 when the detection temperature falls below the temperature T2, and stops the output of the first temperature detection signal 11 when it falls below the temperature T1. Note that only the second temperature detection signal 12 may be output at the temperature T2 or higher, or both the first and second temperature detection signals 11 and 12 may be output.

  Reference numeral 2 denotes a motor drive transistor circuit as a motor drive current generating means for generating a motor drive current for defining the rotation operation and brake operation of the motor to drive the motor. For example, when the motor is an optical disk rotation motor in an optical disk device, a command for instructing a rotation operation such as a 1 × speed mode, a 2 × speed mode, or a 3 × speed mode, or a brake operation such as a reverse brake or a short brake is provided outside the semiconductor device. Is input. The motor drive transistor circuit 2 generates a motor drive current corresponding to a command from the outside during normal operation. In FIG. 1, the transistor inside the motor drive transistor 2 is represented by an NPN transistor. However, the present invention is not limited to this and may be a MOS transistor, for example.

  Reference numeral 3 denotes a motor. The motor drive transistor circuit 2 rotates the motor 3 by passing a motor drive current through a motor coil inside the motor 3. Here, the motor coil is a three-phase coil, and the motor drive transistor circuit 2 rotates the motor by flowing a drive current whose phase is shifted by 120 ° to each coil (each phase). Note that the torque increases by increasing the current value of the drive current passed through each phase, and high-speed rotation is possible by reducing the current cycle.

  Reference numeral 4 denotes a current detector as motor drive current detection means for detecting a motor drive current generated by the motor drive transistor circuit 2. Reference numeral 5 denotes a motor drive transistor control circuit as control means for controlling the motor drive transistor circuit 2. Specifically, the motor drive transistor control circuit 5 generates a control signal for controlling the on / off state (on / off operation) of each transistor in the motor drive transistor circuit 2 and drives each transistor to drive the motor. The transistor circuit 2 is caused to generate a predetermined motor driving current. For example, when the motor is an optical disk rotation motor in an optical disk device, when a command such as a double speed mode or a quadruple speed mode is input from the outside, the motor is configured to generate a motor control current for rotating the motor 3 according to the command. Control the drive transistor circuit. By this control, the motor 3 rotates in a predetermined direction (forward rotation direction) at a desired rotation speed.

  In addition, the motor drive transistor control circuit 5 receives the detection result of the current detector 4, and during normal operation in which the first and second temperature detection signals 11 and 12 are not output from the temperature detection circuit 1, the motor drive current Is limited by the first upper limit value (upper limit value during normal operation), so that the motor drive current becomes too large to prevent the motor from rotating abnormally.

  In addition, the motor drive transistor control circuit 5 has a second lower than the first upper limit value while the first temperature detection signal 11 is output from the temperature detection circuit 1 (during the first temperature control). The motor drive transistor circuit 2 is controlled so as to generate a motor drive current limited by an upper limit value (upper limit value during the first temperature control).

  Further, the motor drive transistor control circuit 5 is configured so that the motor drive current is not generated while the second temperature detection signal 12 is output from the temperature detection circuit 1 (during the second temperature control). 2 is controlled.

  As described above, when the internal temperature of the motor driving semiconductor device increases due to heat generation and reaches the temperature T1, the motor driving current is limited by an upper limit value lower than the upper limit value during normal operation, thereby suppressing heat generation. Perform temperature control to lower the internal temperature.

  Further, when the internal temperature rises to the temperature T2 even though the upper limit value of the motor drive current is limited, the motor drive current is prevented from flowing into the motor drive transistor circuit 2 (shutdown) to suppress heat generation, and the internal temperature The temperature is controlled to lower the temperature.

Here, the reason why heat generation is suppressed by limiting the motor driving current or shutting down the motor driving current will be described. As shown in the following formula (1), the heat generation amount is proportional to the power consumption.
Q∝V × I × t (1)
However, “Q” is a calorific value, “V” is a voltage, “I” is a current, and “t” is a time during which the current is applied.

  In the motor drive semiconductor device, the motor drive transistor circuit 2 has the largest power consumption. Therefore, heat generation is suppressed by limiting or shutting down the motor drive current flowing through the motor drive transistor circuit 2.

  Next, a method for limiting the motor drive current will be described with reference to FIG. FIG. 2 shows an example of a schematic of the motor drive semiconductor device according to the first embodiment. In FIG. 2, 13 indicates the output voltage of the current detector 4. Here, the current detector 4 detects a motor driving current flowing in the motor driving transistor circuit 2 and outputs a voltage corresponding to the current value (current amount).

  Reference numeral 14 denotes an external torque command voltage, and 201 denotes an amplifier as a torque command voltage generation circuit that takes the difference between the external torque command voltage and the voltage from the motor drive current detection means and generates a torque command voltage. The amplifier 201 amplifies the difference between the external torque command voltage and the voltage from the current detector 4 and outputs a torque command voltage.

  Reference numeral 202 denotes a torque limiter that outputs the torque command voltage from the amplifier 201 by limiting it with a torque limit voltage (limit value). The torque limiter 201 has a predetermined first torque limit voltage (first limit value) and a second torque limit voltage (second limit value) lower than the first torque limit voltage, and detects temperature. While the first temperature detection signal 11 is input from the circuit 1, the torque command voltage from the amplifier 201 is limited by the second torque limit voltage and output.

  In addition, while the first temperature detection signal 11 is not input from the temperature detection circuit 1, the torque command voltage from the amplifier 201 is limited by the first torque limit voltage and output. By the limitation by the first torque limit voltage, the motor drive current can be limited by the first upper limit value, and the motor drive current can be prevented from becoming excessively large during normal operation.

  On the other hand, while the first temperature detection signal 11 is output from the temperature detection circuit 1, the torque command voltage from the amplifier 201 is set to the second lower than the torque limit voltage (first torque limit voltage) during normal operation. The output is limited by the torque limit voltage. Thus, by lowering the limit value of the torque command voltage, the upper limit value of the motor drive current can be limited lower than that during normal operation, and the motor drive current limited by the second upper limit value is generated.

  Reference numeral 203 denotes a transistor control signal generation circuit as a motor drive control circuit that controls the motor drive transistor circuit 2 based on the torque command voltage from the torque limiter 201. The transistor control signal generation circuit 203 generates and outputs a control signal for controlling the on / off state of each transistor in the motor drive transistor circuit 2 based on the torque command voltage.

  Further, the transistor control signal generation circuit 203 turns on / off each transistor in the motor drive transistor circuit 2 so that the motor drive current is not generated while the second temperature detection signal 12 is input from the temperature detection circuit 1. A control signal for controlling the off state is generated and output.

  The motor drive transistor control circuit 5 configured as described above controls the motor drive transistor circuit 2 so that the motor 3 rotates according to the external torque command voltage during normal operation, but an abnormality occurs in the external torque command voltage 14. When an excessive torque command voltage is input, the motor drive current is prevented from becoming too large due to the first torque limit voltage. On the other hand, while the first temperature detection signal 11 is being output, the second torque limit voltage is limited by the second torque limit voltage regardless of the external torque command voltage 14, so that the second upper limit is set. A motor drive current limited by value is generated. Further, while the second temperature detection signal 12 is being output, the motor drive transistor circuit 2 is controlled so that no motor drive current is generated regardless of the external torque command voltage 14.

  According to the first embodiment, it is possible to suppress heat generation more than during normal operation while continuing to drive the motor 3. That is, before reaching the temperature at which the motor drive current must be shut down, heat generation can be suppressed without relying on external control, and it is possible to avoid a motor control disabled state due to shutdown.

  Even when a command to drive the motor with high torque is input from the outside of the motor drive semiconductor device, the motor drive current can be limited to an upper limit value lower than the upper limit value during normal operation. Heat generation can be further suppressed. For example, when the motor is an optical disk rotation motor in an optical disk device, if the second torque limit voltage value is made to correspond to the 1 × speed mode (normal rotation mode), when the internal temperature rises at the high speed, it automatically Heat generation can be suppressed by rotating the motor normally (normal speed).

(Embodiment 2)
Next, the motor drive semiconductor device according to the second embodiment will be described.
The motor drive semiconductor device is characterized in that a temperature detection circuit with hysteresis is used as the temperature detection circuit. That is, since the output and release (stop) of the first and second temperature detection signals may be repeated when the internal temperature is in the vicinity of the first and second temperatures T1 and T2, in the motor driving semiconductor device, The temperature detection circuit with hysteresis is used so that the temperature detection signal is stably output even in the vicinity of the first and second temperatures, so that more stable temperature control can be performed.

The function of the temperature detection circuit with hysteresis will be described below.
The temperature detection circuit with hysteresis outputs a first temperature detection signal when the semiconductor device for driving the motor generates heat and the internal temperature reaches the temperature T1. During the output of the first temperature detection signal, when the internal temperature drops by a certain value from the first temperature T1 and reaches the temperature T3, the output of the first temperature detection signal is canceled (stopped).

  The temperature detection circuit with hysteresis outputs a second temperature detection signal when the internal temperature of the motor driving semiconductor device further rises from the temperature T1 to the temperature T2. During the output of the second temperature detection signal, when the internal temperature drops by a certain value from the second temperature T2 to the temperature T4, the output of the second temperature detection signal is canceled (stopped).

According to the second embodiment, the first temperature detection signal is stably output even when the internal temperature is in the vicinity of the first temperature T1, so that the motor can be stably operated even in the vicinity of the first temperature T1. Can be rotated. On the other hand, since the second temperature detection signal is stably output near the second temperature T2, the motor driving current flows or does not flow near the second temperature T2. Can be avoided.
(Embodiment 3)
Subsequently, the motor drive semiconductor device according to the third embodiment will be described.

FIG. 3 is a schematic block diagram of the motor driving semiconductor device according to the third embodiment. However, the same members as those described with reference to FIG.
Conventionally, there are reverse brake and short brake as brake control. The short brake is a brake that makes all the transistors on the source side and all the transistors on the sink side of the motor drive transistor circuit 2 conductive in accordance with the rotation of the motor and stops the motor rotation by the self-generated power of the motor. Therefore, the motor drive current during short braking decreases from the start of brake control, and heat generation is unlikely.

  On the other hand, the reverse brake is a brake that stops motor rotation by forcibly flowing a motor drive current in the reverse direction. Therefore, back electromotive force is generated in the motor coil during reverse braking. The following expression (2) is an approximate expression of the motor drive current Im during forward rotation, and expression (3) is an approximate expression of the motor drive current Im during reverse rotation braking.

Im≈ (Vcc-E) / Ron (2)
Im≈ (Vcc − (− E)) / Ron (3)
However, “Vcc” is a power supply voltage supplied to each transistor in the motor drive transistor circuit 2, “E” is an electromotive force generated by rotation of the motor, “−E” is a reverse power, and “Ron” is a motor drive transistor. The on-resistance of each transistor in the circuit 2.

  As is apparent from the above two equations, during reverse rotation braking, a greater amount of motor drive current flows than during normal rotation due to counter electromotive force generated in the motor coil. Therefore, the motor driving semiconductor device is configured to prohibit the reverse brake and use only the short brake while the temperature detection circuit 1 detects the first temperature T1 or higher. Thereby, the heat_generation | fever at the time of a brake can be suppressed. While the second temperature T2 or higher is detected, heat generation is suppressed by shutting down the motor drive current as in the first and second embodiments.

  In FIG. 3, 15 indicates an external brake command. As the external brake command 15, either a short brake command or a reverse brake command is input. Reference numeral 301 denotes a brake control circuit. When the external brake command 15 is input, the brake control circuit 301 generates a short brake control command signal or a reverse brake control command signal according to the external brake command 15 while the first temperature detection signal 11 is not output. This is output to the control signal generation circuit 203. On the other hand, while the first temperature detection signal 11 is being output, only the short brake control command signal is output to the transistor control signal generation circuit 203 regardless of the external brake command 15.

  When a short brake control command signal or a reverse brake control command signal is input, the transistor control signal generation circuit 203 generates a motor drive current according to the command signal while the second temperature detection signal 12 is not output. Thus, a control signal for controlling the on / off state (operation) of each transistor in the motor drive transistor circuit 2 is generated.

  That is, when a short brake control command signal is input, the transistor control signal generation circuit 203 performs control to turn on all the transistors on the source side and all the transistors on the sink side of the motor driving transistor circuit 2 in accordance with the rotation of the motor. Generate and output a signal. On the other hand, when a reverse brake control command signal is input, a control signal for controlling the on / off state of each transistor in the motor drive transistor circuit 2 is generated and output so that the motor drive current in the reverse direction flows.

  According to the third embodiment, when the internal temperature during braking is equal to or higher than the temperature T1 and lower than the temperature T2, the reverse brake is prohibited and the brake control is performed only by the short brake, so the heat generation is suppressed and the temperature is lowered. Can be made.

  The semiconductor device for driving a motor according to the present invention can suppress heat generation while continuing to drive the motor, and is useful for a circuit for controlling driving of the motor.

Schematic block diagram of the motor drive semiconductor device in the first embodiment of the present invention. The figure which shows an example of the outline of the semiconductor device for motor drive in Embodiment 1 of this invention Schematic block diagram of a motor drive semiconductor device in Embodiment 3 of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Temperature detection circuit 2 Motor drive transistor circuit 3 Motor 4 Current detector 5 Motor drive transistor control circuit 11 1st temperature detection signal 12 2nd temperature detection signal 13 Output voltage of current detector 14 External torque command voltage 15 External brake Command 201 Amplifier 202 Torque limiter 203 Transistor control signal generation circuit 301 Brake control circuit

Claims (6)

Motor drive current generating means for driving the motor by generating a motor drive current that regulates the rotation operation and brake operation of the motor;
A temperature that outputs a temperature detection signal when the detected temperature is equal to or higher than a predetermined constant temperature, and stops output of the temperature detection signal when the detected temperature falls below the predetermined constant temperature or when the detected temperature drops by a predetermined value from the predetermined constant temperature. Detection means;
Motor drive current detection means for detecting motor drive current generated by the motor drive current generation means;
Control means for controlling the motor drive current generating means so as to generate a motor drive current limited by a predetermined upper limit value while the temperature detection signal is being output;
A semiconductor device for driving a motor, comprising: The semiconductor device for motor drive according to claim 1,
The motor drive current detection means detects a motor drive current generated by the motor drive current generation means and outputs a voltage corresponding to the current value.
The control means includes
A torque command voltage generation circuit that takes the difference between the external torque command voltage and the voltage from the motor drive current detection means and generates a torque command voltage;
While the temperature detection signal is being output, a torque limiter that outputs the torque command voltage with a predetermined limit value, and
A motor drive control circuit for controlling the motor drive current generation means based on a torque command voltage from the torque limiter,
While the temperature detection signal is output, the torque command voltage from the torque command voltage generation circuit is limited by a predetermined limit value so that a motor drive current limited by a predetermined upper limit value is generated. A semiconductor device for driving a motor. The semiconductor device for driving a motor according to claim 2.
When a short brake command or a reverse brake command is input as an external brake command, the control means outputs a short brake control command signal or a reverse brake control command according to the external brake command while the temperature detection signal is not output. A brake control circuit that outputs a signal to the motor drive control circuit and outputs a short brake control command signal to the motor drive control circuit while the temperature detection signal is being output;
The motor drive control circuit has a function of controlling the motor drive current generating means so as to generate a motor drive current according to the command signal when a short brake control command signal or a reverse brake control command signal is input.
A semiconductor device for driving a motor. Motor drive current generating means for driving the motor by generating a motor drive current that regulates the rotation operation and brake operation of the motor;
When the detected temperature is equal to or higher than the first constant temperature, a first temperature detection signal is output. When the detected temperature is equal to or higher than the second temperature higher than the first temperature, a second temperature detection signal is output. When the temperature falls below a certain temperature of 2 or when a certain value falls from the second temperature, the output of the second temperature detection signal is stopped, and when the detected temperature falls below the first temperature, or the first Temperature detection means for stopping the output of the first temperature detection signal when a constant value is lowered from the constant temperature of
Motor drive current detection means for detecting motor drive current generated by the motor drive current generation means;
While the first temperature detection signal is being output, the motor drive current generating means is controlled so as to generate a motor drive current limited by a predetermined upper limit value, and the second temperature detection signal is output. Control means for controlling the motor drive current generation means so that no motor drive current is generated by the motor drive current generation means,
A semiconductor device for driving a motor, comprising: The semiconductor device for driving a motor according to claim 4,
The motor drive current detection means detects a motor drive current generated by the motor drive current generation means and outputs a voltage corresponding to the current value.
The control means includes
A torque command voltage generation circuit that takes the difference between the external torque command voltage and the voltage from the motor drive current detection means and generates a torque command voltage;
A torque limiter that limits and outputs a torque command voltage with a predetermined limit value while the first temperature detection signal is being output;
While the second temperature detection signal is not output, the motor drive current generating means is controlled based on the torque command voltage from the torque limiter, and the second temperature detection signal is output. Comprises a motor drive control circuit that controls the motor drive current generation means so that no motor drive current is generated by the motor drive current generation means,
While the first temperature detection signal is being output, the torque command voltage from the torque command voltage generation circuit is limited by a predetermined limit value, thereby generating a motor drive current limited by a predetermined upper limit value. The motor drive semiconductor device is characterized in that the motor drive current is not generated by the motor drive current generation means while the second temperature detection signal is output. The semiconductor device for driving a motor according to claim 5,
When a short brake command or a reverse brake command is input as an external brake command, the control means performs a short brake control command signal or reverse rotation according to the external brake command while the first temperature detection signal is not output. A brake control circuit that outputs a brake control command signal to the motor drive control circuit and outputs a short brake control command signal to the motor drive control circuit while the first temperature detection signal is output; ,
When the short brake control command signal or the reverse brake control command signal is input, the motor drive control circuit generates a motor drive current according to the command signal while the second temperature detection signal is not output. A function of controlling the motor driving current generating means,
A semiconductor device for driving a motor.

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