JP2923141B2 - Motor drive control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an 8 mm VTR,
The present invention relates to a motor drive control device that drives and controls a motor used for a DAT, a CD, and the like.

[0002]

2. Description of the Related Art As an apparatus used for controlling an 8 mm VTR or the like, there is an apparatus as shown in FIG. 2, for example. In this figure, a three-phase (U, V, W) motor 10 is shown as a motor to be controlled. The motor drive control IC 12 is an IC for controlling the motor 10, and has three output terminals corresponding to each phase of the motor 10, namely, V _OUT (U), V _OUT (V), and V _OUT (V).
_OUT (W). This output terminal V _OUT (U),
The output terminals of the corresponding drive control circuits 14U, 14V, 14W are connected to V _OUT (V) and V _OUT (W).

[0003] The drive control circuits 14U, 14V, 14W are:
Source-side power transistors 16U, 16V or 16W and sink-side power transistors 18U,
8V or 18W is provided. Drive control circuit 14U,
The output terminals of 14V and 14W are connection points of these source-side power transistors 16U, 16V or 16W and sink-side power transistors 18U, 18V or 18W. Source side power transistors 16U, 16V and 1
6W is connected to the motor power supply terminal V _S, motor power V _S is the source-side power transistors 16U, is supplied to the 16V and 16W through the terminal V _S. Also,
Sink side power transistors 18U, 18V and 18W
Is connected to a feedback resistor Rf via a motor ground terminal Rf. This feedback resistor Rf is a resistor that converts a supplied current into a voltage and feeds it back to the drive control circuits 14U, 14V and 14W.

These three drive control circuits 14U, 14V
And 14W are controlled by a source side control current and a sink side control current. The source-side control current and the sink-side control current are currents set according to the load of the motor 10. The source-side control current is supplied to the source-side power transistors 16U, 16V, and 16W, and the sink-side control current is the sink-side control current. Power transistors 18U, 18V and 1
8W.

Drive control circuits 14U, 14V and 14W
Have a configuration as shown in FIG. 3, for example. As shown in this figure, the source-side control current is supplied to the current amplification circuit 22 via the current mirror circuit 20. The current amplification circuit 22 includes the input-side transistor 2
4 and a current mirror circuit composed of an output transistor 26, and the collector of the output transistor 26 is connected to the transistor 28. Transistor 2
8 is current mirror connected to the source side power transistor 16,
6 together with the source-side drive circuit 30. on the other hand,
The sink-side control current is supplied to the current amplification circuit 34 via the current mirror circuit 32. The current amplifier circuit 34
36 input transistors and 38 output transistors
The collector of the transistor 38 is connected to the collector of the transistor 40. The transistor 40 is current-mirror-connected to the sink-side power transistor 18, and forms a sink-side drive circuit 42 together with the sink-side power transistor 18.

The current amplifier circuits 22 and 34 are respectively
The supplied current is amplified to n ₁ times or n ₂ times and supplied to the source side drive circuit 30 or the sink side drive circuit 42. Source-side drive circuit 30 and sink-side drive circuit 42
Amplify the supplied current by n ₃ times. The current output from the source-side drive circuit 30 and the sink-side drive circuit 42 is supplied to the coil of the motor 10 via the output terminal V _OUT . n _1, for example about 20 to 30, n ₃ is an example, about 50, n ₂ is set to a value different from the n ₁ generally.

FIG. 4 shows an output voltage waveform in this conventional example. When a constant current is supplied to the coil of the motor 10, an output voltage as shown in this figure appears at the output terminal V _OUT . In particular, (a) shows a waveform when n ₁ <n ₂ , and (b) shows a waveform when n ₁ > n ₂ .

In the conventional example described above, that is, in the configuration in which the source side power transistor 16 and the sink side power transistor 18 are NPN transistors, V _S ≧ V _CC
When the so-called rest voltage with for motor power V _S is increased there has been a problem that increases. That is, as shown in FIG. 5A, the output voltage V _OUT is always equal to the sum of the collector-emitter voltage V _{CE1 of the} transistor 26 and the base-emitter voltage V _BE of the source-side power transistor 16. Accordingly, the collector-emitter saturation voltage of the transistor 26 V _CESAT1, if the threshold of the base-emitter voltage of the source-side power transistor 16 and the V _F, the following relation is established. V _OUT <V _CC − (V _CESAT1 + V _F ) (1) The output voltage V _OUT is the collector-emitter voltage V _S of the source side power transistor 16 with respect to the motor power supply V _S.
It has a lower value by _CE2 . Therefore, the collector-emitter saturation voltage of the source side power transistor 16 is set to V
_When expressed as _CESAT2 , the following relationship holds.

V _OUT <V _S −V _CESAT2 (2) On the other hand, output voltage V _OUT , motor power supply V _S , control power supply V _CC
Have a relationship as shown in FIG. 5B, for example. In this figure, the motor power supply V _S and the output voltage V _OUT
Is usually called an output remaining voltage. In the configuration of FIG. 3, by varying the motor power V _S, that is, by using the motor power V _S as the speed control voltage to vary the output voltage V _OUT, although it is possible to control the speed of the motor 10 As is apparent from the equations (1) and (2), the motor power supply V _S is _equal to V _CC −
When it exceeds V _F , the output voltage V _OUT does not rise,
The remaining voltage increases. This means that the speed control range of the motor 10 is limited by the equations (1) and (2).

In order to overcome such a limitation, for example, a configuration as shown in FIG. 6 may be used. The circuit shown in this figure is a circuit shown in FIG.
Unlike the above configuration, a PNP transistor is used. In response to this, the transistor 28 is changed to a PNP transistor, the transistors 24 and 26 are changed to NPN transistors, respectively, and the emitters of the transistors 24 and 26 are grounded. Hereinafter, in order to distinguish from the configuration of FIG. 3, transistors 16, 24, 26 and 2 in FIG.
8, the reference numerals of the current amplification circuit 22 and the source-side drive circuit 30 are denoted by '.

With such a configuration, the restriction on the output voltage V _{OUT by} the control power supply V _CC can be released. That is, the input-side transistor 28 'of the source-side drive circuit 30' is not connected to the control power supply V _CC , thereby avoiding the above-described limitation.

[0012]

However, in a circuit having such a configuration, that is, a configuration in which the source-side power transistor 16 'is a PNP transistor and the sink-side power transistor 18 is an NPN transistor, another new problem arises. I do.

As shown in FIG. 7, when a base-emitter voltage of the source-side power transistor 16 'is expressed as V _BE and a collector-emitter voltage of the transistor 26' is expressed as V _CE3 , V _S = V _BE + V _CE3. Holds. _Assuming that the threshold value of V _BE is V _F and the saturation voltage between the collector and the emitter of the transistor 26 ′ is V _CESAT3 , the source side power transistor 16 ′ is driven unless V _S > V _F + V _CESAT3. Can not do.
That is, in the reference example shown in FIG. 6, it can not be driving the motor 10 when the motor power supply V _S is low. The following table summarizes the problems of FIG. 3 and FIG. However, the sum of the In Table 0.8 the sum of V _CESAT1 the V _F and the transistor 26 of the source-side power transistor 16 (V), V _{CESA T3} of V _F and the transistor 26 'of the source-side power transistor 16' To 0.8
(V).

[0014]

[Table 1] The present invention has it been made as object to solve the above problems, to provide a suitably driven controllable drive controller also motor in either motor power V _S is higher regions and lower regions The purpose is to:

[0015]

In order to achieve the above object, a motor drive control device according to the present invention is provided including an NPN transistor connected between a speed control voltage input terminal and an output terminal. A first source-side drive circuit for amplifying the current and supplying it to the motor coil from the output terminal; and an NPN transistor connected between the output terminal and the ground terminal. And a first current supplied to the first source-side drive circuit by amplifying the source-side control current and including a PNP transistor connected between the control power supply terminal and the first source-side drive circuit An amplifier circuit, a second current amplifier circuit connected between the control power supply terminal and the sink side drive circuit for amplifying the sink side control current and supplying the amplified current to the sink side drive circuit; A second source-side drive circuit including a PNP transistor connected between the voltage input terminal and the output terminal for amplifying the supplied current and supplying the amplified current to the motor coil from the output terminal; A third current amplifying circuit connected to the second source-side driving circuit for amplifying the source-side control current and a first current amplifying circuit when the speed control voltage is low, and a third current amplifying circuit when the speed control voltage is high. 3
Switching means for supplying a source-side control current to the current amplifier circuit.

[0016]

In the present invention, the sink-side control current is equal to the second control current.
After being amplified by the current amplifier circuit, it is supplied to the sink side drive circuit. The sink-side drive circuit amplifies the supplied current and supplies the amplified current to the motor coil from the output terminal.

In the present invention, the supply destination of the source side control current is switched by the switching means. First,
When the speed control voltage is low, the switching means supplies the source-side control current to the first current amplification circuit. The first current amplification circuit amplifies the supplied source-side control current, and
Supply to source side drive circuit. The first source-side drive circuit amplifies the supplied current and supplies the amplified current to the motor coil from the output terminal.

When the speed control voltage is high, the switching means supplies the source-side control current to the third current amplifier. The third current amplifier circuit amplifies the source-side control current and supplies the amplified current to the second source-side drive circuit, and the second source-side drive circuit amplifies the supplied current and supplies the amplified current to the motor coil from the output terminal.

Accordingly, in the present invention, when the speed control voltage is low, the source NPN-sink NPN,
When the speed control voltage is high, the motor is driven and controlled by the configuration of the source-side PNP and the sink-side NPN, so that the controllable range becomes wider than the motor control voltage.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. The same components as those of the conventional example shown in FIGS. 2 to 5 and the reference examples shown in FIGS. 6 and 7 are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 1 shows a configuration of a drive control circuit according to an embodiment of the present invention. As shown in this figure, this embodiment uses 30 and 3 as source side drive circuits.
0 '. Along with this, both current amplifier circuits 22 and 22 'for supplying current to the source side drive circuits 30 and 30' are provided. This embodiment is characterized in that the source-side NPN
- In addition to having both the configuration of the sink side NPN, a configuration of the source-side PNP- sink NPN, these is to switching used in accordance with the value of the motor power V _S.

As shown in FIG. 2, this embodiment includes transistors 46 and 48 which receive a source-side control current from a current mirror circuit 44. The base of the transistor 46 is (are α constant) alpha] V _S are applied, the reference voltage V _R is applied to the base of transistor 48. The emitters of transistors 46 and 48 are
The current mirror circuit 44 is connected to the current mirror circuit 44 via a resistor 50 or 52 for determining the gain, and the collector is connected to the current mirror circuit 20 or the current amplifier circuit 22 ', respectively.

Therefore, when the motor power supply V _S is low, that is, when αV _S is lower than V _R , the source-side control current is exclusively generated by the transistor 46 and the current mirror circuit 20.
Is supplied to the current amplifying circuit 22 through the current amplifying circuit 22. In the opposite case, the current amplifying circuit 22 is supplied through the transistor 48.
′. In other words, if the motor power V _S is low, a current is supplied to the motor coil using a source side driving circuit 30 and the sink-side drive circuit 42,
Further, the current is supplied to the motor coil using a source side driver circuit 30 'and the sink-side drive circuit 42 when the motor power supply V _S is high.

Therefore, in this embodiment, V _s ≧ V _CC
−V _F , even when the voltage is −V _F
And the drive of the motor 10 can be controlled using the sink-side drive circuit 42, and V _s ≦ V _F + V _CESAT3
In this case, the drive of the motor 10 can be controlled using the source-side drive circuit 30 and the sink-side drive circuit 42. In other words, the control range of the speed of the motor 10 by the motor power supply V _S is widened, and even when the motor power supply V _S is in the range of 0 V to 0.8 V, V _CC −0.
Even at 8 V or more, the motor 10 can be driven and its speed can be controlled. Therefore, a wide range is required as the speed control range of the motor 10. A circuit which can be suitably used for an 8 mm VTR or the like can be realized.

The transistors 46 and 48 may be replaced by a comparator.

[0026]

As described above, according to the present invention,
The source of the source-side control current is switched so that the motor is drive-controlled by the source-side NPN-sink-side NPN when the speed control voltage is low, and by the source-side PNP-sink-side NPN when the speed voltage is high. As a result, a motor drive control device in which the control range of the motor speed is expanded can be obtained.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration of a motor circuit according to one embodiment of the present invention.

FIG. 2 is a circuit diagram showing a usage mode of a motor drive control IC.

FIG. 3 is a circuit diagram of a circuit according to a conventional example.

FIG. 4 is a diagram showing an output voltage waveform in the conventional example.

FIG. 5 is a diagram showing a problem of the conventional example.

FIG. 6 is a circuit diagram showing a configuration of a circuit according to a reference example.

FIG. 7 is a diagram showing a problem of the reference example.

[Explanation of symbols]

Reference Signs List 10 motor 12 motor drive control IC 14 drive control circuit 16 source side power transistor (NPN) 16 'source side power transistor (PNP) 18 sink side power transistor 20, 32, 44 current mirror circuit 22, 22', 34 current amplification Circuits 24, 24 ', 36 Input-side transistors 26, 26', 38 Output-side transistors 28, 28 'of current-amplification circuits Input-side transistors of source-side drive circuits 40 Input-side transistors 46 of sink-side drive circuits, 48 Source-side drive circuit switching transistor

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Atsushi Kikuchi 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Toshiya Nakabayashi 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo No. Sony Corporation (58) Fields surveyed (Int.Cl. ⁶ , DB name) H02M 7/42-7/98 H02M 1/08 H02P 7/63 H02P 5/41

Claims (1)

(57) [Claims] A first source-side drive circuit including an NPN transistor connected between a speed control voltage input terminal and an output terminal, for amplifying a supplied current and supplying the amplified current from an output terminal to a motor coil; Drive circuit including an NPN transistor connected between the power supply terminal and the ground terminal, amplifying the supplied current and supplying the amplified current from the output terminal to the motor coil, and connected between the control power supply terminal and the first source side drive circuit A first current amplifier circuit including a PNP transistor, and amplifying a source-side control current and supplying the amplified current to a first source-side drive circuit; a first power amplifier circuit connected between a control power supply terminal and a sink-side drive circuit; And a second current amplifier circuit for amplifying and supplying the amplified current to the sink-side drive circuit, wherein the motor drive control device is connected between the speed control voltage input terminal and the output terminal. A second source-side drive circuit including a PNP transistor for amplifying a supplied current and supplying the amplified current to the motor coil from an output terminal; a second source-side drive circuit connected between the second source-side drive circuit and a ground plane to amplify the source-side control current; A third current amplifying circuit for supplying the second current to the second source side driving circuit, and a first current amplifying circuit when the speed control voltage is low.
Switching means for supplying a source-side control current to the third current amplifier circuit when the power is high.