WO2022113673A1 - Motor driving circuit - Google Patents

Motor driving circuit Download PDF

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Publication number
WO2022113673A1
WO2022113673A1 PCT/JP2021/040467 JP2021040467W WO2022113673A1 WO 2022113673 A1 WO2022113673 A1 WO 2022113673A1 JP 2021040467 W JP2021040467 W JP 2021040467W WO 2022113673 A1 WO2022113673 A1 WO 2022113673A1
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Prior art keywords
motor
reference potential
circuit
current detection
pattern
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PCT/JP2021/040467
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French (fr)
Japanese (ja)
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健一 伊藤
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株式会社村田製作所
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Priority to JP2022565170A priority Critical patent/JP7400992B2/en
Publication of WO2022113673A1 publication Critical patent/WO2022113673A1/en

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/16—Modifications for eliminating interference voltages or currents

Definitions

  • the present invention relates to a motor drive circuit configured by connecting a current detection resistor to a switch that switches the drive current supplied to the motor.
  • Patent Document 1 Conventionally, as a motor drive circuit of this type, for example, there is one disclosed in Patent Document 1.
  • the direction of the current supplied to the motor is controlled by switching the MOS transistor constituting the H-bridge circuit, and the motor rotates forward or reverse.
  • a wiring resistance is connected between the grounds of the H-bridge circuit and the motor drive circuit as a current detection resistance at a position close to the H-bridge circuit and the ground, and a voltage corresponding to the current flowing through the motor is generated between the terminals of the wiring resistance. ..
  • the drive control unit composed of a logic circuit or the like controls the H-bridge circuit according to the voltage generated in the wiring resistance, and controls the current supply to the motor.
  • the present invention has been made to solve such a problem, and is a switch for switching the drive current supplied to the motor.
  • a current detection resistor with one end connected to the reference potential that detects the current flowing through the switch in the vicinity of the switch.
  • a drive control circuit that controls switch switching based on the voltage between the terminals of the current detection resistor, A reference potential pattern that gives a reference potential to the drive control circuit,
  • a motor drive circuit is configured in which the circuit board is provided with a wiring pattern in which one end of the current detection resistance is connected to a reference potential pattern at a predetermined distance from the switch.
  • switching noise is transmitted from the switch through the current detection resistance and the wiring pattern to the connection point with the reference potential pattern of the wiring pattern. Further, the switching noise is emitted from the switch into space and flies to the connection point of the wiring pattern with the reference potential pattern.
  • one end of the current detection resistor is connected to the reference potential pattern at a predetermined distance from the switch by the wiring pattern, and the reference potential is given. Therefore, the switching noise conducted through the wiring pattern is attenuated along the wiring pattern to the connection point with the reference potential pattern. Further, the switching noise propagating in space is attenuated by the time it flies through space and reaches the connection point with the reference potential pattern of the wiring pattern. Therefore, at the connection point of the wiring pattern with the reference potential pattern, the reference potential is less likely to be affected by switching noise and is kept substantially constant.
  • FIG. 2 is a block diagram showing a schematic configuration of a motor drive circuit 1 according to an embodiment of the present invention.
  • the motor drive circuit 1 is configured on the circuit board 2 and is connected to the motor coils 3a, 3b, 3c of each phase of the three-phase brushless motor 3.
  • the motor drive circuit 1 includes drive (driver) circuits 5a, 5b, 5c for the motor coils 3a, 3b, 3c of each phase, and supplies the motor coils 3a, 3b, 3c under the control of the control circuit 6.
  • the drive current i to be driven is controlled by 3-phase PWM (Pulse Width Modulation).
  • Each driver circuit 5a, 5b, 5c is composed of a power MOSFET (field effect transistor) 4a, 4b and a current detection resistor R connected in series, respectively.
  • a current detection resistor R is connected to the source terminal of each FET 4b, and a drive current i flows through the motor coils 3a, 3b, 3c. va occurs.
  • the current detection resistance R may be a resistance element, or may be configured by a wiring resistance of a wiring pattern formed of a conductive film on the surface of the circuit board 2.
  • the resistance value of the current detection resistor R is set to 10 [m ⁇ ].
  • This voltage between terminals va is input between a pair of input terminals of each differential amplifier circuit 8 configured in a packaged drive (driver) control IC (integrated circuit) 7.
  • the driver control IC 7 includes a comparator 9, a logic circuit 10, a high-side gate driver 11, and a low-side gate driver 12.
  • Each differential amplifier circuit 8 amplifies the input voltage va into a voltage Vref, and outputs the amplified voltage Vref to one of the non-inverting input terminals of each comparator 9.
  • a predetermined reference voltage Vc is given to the other inverting input terminal of each comparator 9.
  • Each comparator 9 outputs a high level signal to the logic circuit 10 when the voltage Vref input from the differential amplifier circuit 8 is higher than the reference voltage Vc, and low level when the voltage Vref is lower than the reference voltage Vc. Signal is output to the logic circuit 10.
  • the logic circuit 10 controls each FET 4a and 4b based on the output of each comparator 9. That is, the high-side gate driver 11 and the low-side gate driver 12 are controlled so that no current flows through the motor 3 when the output voltage of the comparator 9 is low level. Further, the high side gate driver 11 and the low side gate driver 12 are controlled so that a current flows through the motor 3 when the output voltage of the comparator 9 is at a high level. That is, the high-side gate driver 11 turns on the switching of one FET 4a on the high-side side constituting any one of the driver circuits 5a, 5b, 5c. The low-side gate driver 12 turns on the switching of one FET 4b on the low-side side that constitutes another driver circuit 5a, 5b, 5c. By this switching, the drive current i supplied to the motor is PWM controlled so as to flow through the motor coils 3a and 3b, the motor coils 3c and 3b, or the motor coils 3c and 3a.
  • each of the FETs 4a and 4b constituting the driver circuits 5a, 5b and 5c constitutes a switch for switching the drive current i supplied to the motor 3.
  • each current detection resistor R detects the current i flowing through each of the FETs 4a and 4b in the vicinity of each of the FETs 4a and 4b.
  • the driver control IC 7 controls the switching of each of the FETs 4a and 4b as described above based on the voltage between the terminals of the current detection resistor R.
  • the ground terminal pin 7a is connected to the reference potential pattern 13 in the immediate vicinity thereof, so that the ground potential is given to the ground terminal pin 7a as the reference potential V0 of the circuit.
  • One end of each current detection resistance R is connected to the reference potential V 0 by being commonly connected to the reference potential pattern 13 at a predetermined distance from the FETs 4a and 4b by the wiring pattern 14.
  • the FETs 4a and 4b and the current detection resistance R are mounted on one side of the driver control IC 7 on the circuit board 2, and the connection point x of the wiring pattern 14 with the reference potential pattern 13 is the same as the one side.
  • Both the reference potential pattern 13 and the wiring pattern 14 are formed by patterning a conductive film such as a copper foil on the surface of the circuit board 2.
  • a noise suppression component 15 such as a ferrite bead inductor is further provided on the substrate surface of the circuit board 2 between the connection point x of the wiring pattern 14 with the reference potential pattern 13 and the substrate ground 16 of the circuit board 2. Be prepared.
  • the substrate ground 16 is formed as a so-called solid pattern on the entire surface of the back surface of the circuit board 2 , for example, and is maintained at a reference potential of V0.
  • the noise suppression component 15 it is preferable to select a component having a high noise suppression effect in the harmonic frequency band of the noise frequency in question, for example, the switching frequency of each of the FETs 4a and 4b.
  • the graph shown in FIG. 3 shows the results of observing the current consumption and the rotation speed of the motor 3 driven by the motor drive circuit 1 according to the above embodiment.
  • the horizontal axis of the graph represents time [msec]
  • the vertical axis on the right side represents motor current consumption [mA]
  • the vertical axis on the left side represents motor rotation speed [rpm].
  • the characteristic line 21 that oscillates finely represents the current consumption of the motor
  • the characteristic line 22 that oscillates greatly in a rectangular shape represents the characteristics of the motor rotation speed.
  • connect a cable to the test pin connector of the IC that constitutes the control circuit 6 connect the cable to an external personal computer (PC), and inside the IC that constitutes the control circuit 6.
  • PC personal computer
  • the rotation of the motor 3 maintains the positive rotation for 1.5 seconds, and then the negative rotation is maintained for 1.5 seconds, so that the operation mode in which the positive rotation and the negative rotation are continuous in time is set. I set it. Further, the rotation speed of the motor 3 was set to 500 to 550 [rpm] for both forward rotation and negative rotation.
  • the graph shown in FIG. 4 shows the results of observing the current consumption and the rotation speed of the motor 3 similarly observed in the conventional motor drive circuit.
  • the current detection resistance R is connected between the FETs 4a and 4b for switching the motor drive current and the substrate ground 16 which is the reference potential at a position close to them.
  • the same or corresponding parts as those in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted.
  • the horizontal axis and each vertical axis of the graph shown in FIG. 4 are the same as the graph shown in FIG.
  • the characteristic line 31 that oscillates finely represents the motor consumption current
  • the characteristic line 32 that oscillates greatly in a rectangular shape represents the characteristics of the motor rotation speed.
  • the characteristic line 31 of the conventional motor consumption current has a larger amplitude over the entire time zone as compared with the characteristic line 21 of the present embodiment, and the conventional motor has a larger amplitude.
  • the switching noise of each of the FETs 4a and 4b is superimposed on the motor current consumption over the entire time zone. Due to this switching noise, the reference potential V 0 of the substrate ground 16 to which one end of the current detection resistor R is connected fluctuates as shown in FIG. 1 (b).
  • the drive current supplied to the motor 3 is switched by each of the FETs 4a and 4b, so that the switching noise is transmitted from each of the FETs 4a and 4b to the substrate ground 16 through the current detection resistor R and the wiring pattern. it is conceivable that. At the same time, it is considered that the switching noise is emitted from each of the FETs 4a and 4b into the space and propagates to the substrate ground 16. Due to this fluctuation of the reference potential V 0 of the substrate ground 16, the voltage Va applied to the differential amplifier circuit 8 does not satisfy a predetermined threshold voltage (for example, 2 [V]) with respect to the reference potential V 0 (for example, 2 [V]). For example, when it becomes 1.8 [V]), the logic circuit 10 cannot discriminate the output of the comparator 9. Therefore, the logic circuit 10 waits for the rotation of the motor 3 until the voltage Va applied to the differential amplifier circuit 8 reaches a predetermined threshold voltage.
  • a predetermined threshold voltage for example, 2 [V]
  • the conventional characteristic line 32 of the motor rotation speed for example, at the position indicated by the ellipse A of the broken line in FIG. 4, there is a time zone in which the motor rotation speed becomes substantially 0, and a current is flowing through the motor 3. , There is a waiting time when the motor 3 is not rotating. As a result, the motor 3 does not continuously and smoothly shift to forward rotation or negative rotation. When the motor 3 rotates in the forward direction, the current consumed by the motor becomes a positive current, and when the motor 3 rotates in the negative direction, a negative current is observed.
  • one end of the current detection resistor R is connected to the connection point x with the reference potential pattern 13 at a predetermined distance via the wiring pattern 14, FIG.
  • the characteristic line 22 of the motor rotation speed of there is no time zone when the motor rotation speed becomes almost 0, and it is observed that the rotation of the motor 3 continuously and smoothly shifts to positive rotation or negative rotation. Will be done.
  • the drive current supplied to the motor 3 is switched by the FETs 4a and 4b, so that the switching noise is transmitted from the FETs 4a and 4b through the current detection resistance R and the wiring pattern 14. , Conducts to the connection point x of the wiring pattern 14 with the reference potential pattern 13. Further, the switching noise is emitted from each of the FETs 4a and 4b into the space and flies to the connection point x of the wiring pattern 14 with the reference potential pattern 13.
  • one end of the current detection resistor R is connected to the reference potential pattern 13 at a predetermined distance from each of the FETs 4a and 4b by the wiring pattern 14, and the reference potential V0 . Is given.
  • the distance between each of the FETs 4a and 4b and the connection point x between the reference potential pattern 13 of the wiring pattern 14 is set to a predetermined distance by arranging them on both sides of the driver control IC 7. Can be opened.
  • the switching noise conducted through the wiring pattern 14 is attenuated while being transmitted through the wiring pattern 14 and reaching the connection point x with the reference potential pattern 13. Further, the switching noise propagating in the space is attenuated by the time it flies through the space and reaches the connection point x with the reference potential pattern 13 of the wiring pattern 14. Therefore, at the connection point x of the wiring pattern 14 with the reference potential pattern 13, the reference potential V 0 is less likely to be affected by the switching noise and is kept substantially constant. As a result, switching noise does not overlap with the input voltage of each differential amplifier circuit 8, and the driver control IC 7 of the motor drive circuit 1 correctly detects the voltage va between the terminals of the current detection resistance R.
  • the motor 3 can be controlled.
  • the switching noise that could not be completely attenuated while propagating in space up to x is further attenuated by the noise suppression component 15. Therefore, the inflow of noise conducted or coupled to the substrate ground 16 is suppressed, and the reference potential V 0 given to one end of the current detection resistor R is further less affected by the switching noise and is kept almost constant. become.
  • the driver control IC 7 of the motor drive circuit 1 can control the motor 3 more accurately based on the voltage va accurately detected between the terminals of the current detection resistance R.
  • the motor 3 is a three-phase brushless motor has been described, but the same can be applied to a motor drive circuit of a single-phase or two-phase brushless motor. Further, it can be similarly applied to a motor drive circuit such as a brushed motor having each phase using an H-bridge circuit. Further, the motor 3 does not necessarily have to rotate in the forward and reverse directions, and is similarly applied to the motor drive circuit of the motor in which the rotation of the motor coils 3a, 3b, and 3c is controlled by rotating and stopping by switching of the switch. be able to. And, in each of these cases, the same action and effect as those of the above-described embodiment are exhibited.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Control Of Motors That Do Not Use Commutators (AREA)
  • Control Of Electric Motors In General (AREA)

Abstract

Provided is a motor driving circuit the driving control circuit of which can correctly control a motor on the basis of a voltage that is precisely detected between the terminals of each of a plurality of current detection resistors. A driver control IC 7 has a ground terminal pin 7a connected to a reference potential pattern 13 in the immediate vicinity thereof, whereby a ground potential is applied, as a reference potential V0 of the circuit, to the ground terminal pin 7a. One ends of the respective current detection resistors R are commonly connected to the reference potential pattern 13 by a wiring pattern 14 with predetermined distances kept from the respective ones of FETs 4a, 4b, thereby being connected to the reference potential V0. In an embodiment, the FETs 4a, 4b and the current detection resistors R are implemented on one side of the driver control IC 7 on a circuit board 2, while a connection point x of the wiring pattern 14 with respect to the reference potential pattern 13 is located at a position near the ground terminal pin 7a of the driver control IC 7 that is on the opposite side to said one side, whereby the predetermined distances can be kept.

Description

モータ駆動回路Motor drive circuit
　本発明は、モータへ供給する駆動電流をスイッチングするスイッチに電流検出抵抗が接続されて構成されるモータ駆動回路に関するものである。 The present invention relates to a motor drive circuit configured by connecting a current detection resistor to a switch that switches the drive current supplied to the motor.
　従来、この種のモータ駆動回路としては、例えば、特許文献１に開示されたものがある。 Conventionally, as a motor drive circuit of this type, for example, there is one disclosed in Patent Document 1.
　同文献に開示されたモータ駆動回路は、Ｈブリッジ回路を構成するＭＯＳトランジスターがスイッチングされることで、モータに供給される電流の向きが制御されて、モータが正転または逆転する。Ｈブリッジ回路およびモータ駆動回路のグランド間には、配線抵抗が電流検出抵抗としてＨブリッジ回路およびグランドに近接する位置に接続され、配線抵抗の端子間にはモータに流れる電流に応じた電圧が生じる。ロジック回路等によって構成される駆動制御部は、この配線抵抗に生じる電圧に応じてＨブリッジ回路を制御し、モータへの電流供給を制御する。 In the motor drive circuit disclosed in the same document, the direction of the current supplied to the motor is controlled by switching the MOS transistor constituting the H-bridge circuit, and the motor rotates forward or reverse. A wiring resistance is connected between the grounds of the H-bridge circuit and the motor drive circuit as a current detection resistance at a position close to the H-bridge circuit and the ground, and a voltage corresponding to the current flowing through the motor is generated between the terminals of the wiring resistance. .. The drive control unit composed of a logic circuit or the like controls the H-bridge circuit according to the voltage generated in the wiring resistance, and controls the current supply to the motor.
特開２０１７－１５８３８７号公報Japanese Unexamined Patent Publication No. 2017-158387
　しかしながら、特許文献１に開示された上記従来のモータ駆動回路では、配線抵抗の一端が接続されるグランドには、Ｈブリッジ回路を構成するＭＯＳトランジスターがスイッチングすることで、ノイズが重畳する。例えば、モータ駆動回路のグランド電位Ｖ０は、ノイズの無い正常時には、図１（ａ）に示すように、配線抵抗によって検出される所定の電圧Ｖａに対して一定に保たれている。しかし、ＭＯＳトランジスターがスイッチングすることで、図１（ｂ）に示すように、モータ駆動回路のグランド電位Ｖ０にはノイズＮが重畳し、グランド電位Ｖ０が乱れる。このようにモータ駆動回路のグランド電位Ｖ０にノイズＮが重畳すると、配線抵抗の端子間に検出される電圧がノイズＮの影響を受けて変動し、モータ駆動回路の駆動制御部は正しくモータを制御できなくなる。 However, in the conventional motor drive circuit disclosed in Patent Document 1, noise is superimposed on the ground to which one end of the wiring resistance is connected by switching the MOS transistor constituting the H-bridge circuit. For example, the ground potential V 0 of the motor drive circuit is kept constant with respect to a predetermined voltage Va detected by the wiring resistance, as shown in FIG. 1A, in the normal state without noise. However, as the MOS transistor switches, as shown in FIG. 1 (b), noise N is superimposed on the ground potential V 0 of the motor drive circuit, and the ground potential V 0 is disturbed. When noise N is superimposed on the ground potential V 0 of the motor drive circuit in this way, the voltage detected between the terminals of the wiring resistance fluctuates under the influence of noise N, and the drive control unit of the motor drive circuit correctly drives the motor. You lose control.
　本発明はこのような課題を解決するためになされたもので
モータへ供給する駆動電流をスイッチングするスイッチと、
スイッチに流れる電流をスイッチの近傍で検出する一端が基準電位に接続される電流検出抵抗と、
電流検出抵抗の端子間電圧に基づいてスイッチのスイッチングを制御する駆動制御回路と、
駆動制御回路に基準電位を与える基準電位パターンと、
電流検出抵抗の一端を前記スイッチから所定の距離をあけて基準電位パターンに接続する配線パターンと
を回路基板に備えるモータ駆動回路を構成した。 The present invention has been made to solve such a problem, and is a switch for switching the drive current supplied to the motor.
A current detection resistor with one end connected to the reference potential that detects the current flowing through the switch in the vicinity of the switch.
A drive control circuit that controls switch switching based on the voltage between the terminals of the current detection resistor,
A reference potential pattern that gives a reference potential to the drive control circuit,
A motor drive circuit is configured in which the circuit board is provided with a wiring pattern in which one end of the current detection resistance is connected to a reference potential pattern at a predetermined distance from the switch.
　モータへ供給される駆動電流がスイッチによってスイッチングされることで、スイッチングノイズが、スイッチから電流検出抵抗および配線パターンを伝って、配線パターンの基準電位パターンとの接続点まで伝導する。また、スイッチングノイズは、スイッチから空間に放出されて、配線パターンの基準電位パターンとの接続点に飛来する。しかし、本構成によれば、電流検出抵抗の一端は、配線パターンによってスイッチから所定の距離をあけて基準電位パターンに接続されて、基準電位が与えられる。したがって、配線パターンを伝導するスイッチングノイズは、配線パターンを伝って基準電位パターンとの接続点に至る間に減衰する。また、空間を伝搬するスイッチングノイズは、空間を飛んで配線パターンの基準電位パターンとの接続点に到達するまでに、減衰する。このため、配線パターンの基準電位パターンとの接続点において、基準電位は、スイッチングノイズの影響を受け難くなり、ほぼ一定に保たれるようになる。 By switching the drive current supplied to the motor by the switch, switching noise is transmitted from the switch through the current detection resistance and the wiring pattern to the connection point with the reference potential pattern of the wiring pattern. Further, the switching noise is emitted from the switch into space and flies to the connection point of the wiring pattern with the reference potential pattern. However, according to this configuration, one end of the current detection resistor is connected to the reference potential pattern at a predetermined distance from the switch by the wiring pattern, and the reference potential is given. Therefore, the switching noise conducted through the wiring pattern is attenuated along the wiring pattern to the connection point with the reference potential pattern. Further, the switching noise propagating in space is attenuated by the time it flies through space and reaches the connection point with the reference potential pattern of the wiring pattern. Therefore, at the connection point of the wiring pattern with the reference potential pattern, the reference potential is less likely to be affected by switching noise and is kept substantially constant.
　この結果、本発明によれば、電流検出抵抗の端子間に正確に検出される電圧に基づいて、駆動制御回路が正しくモータを制御できるモータ駆動回路を提供することができる。 As a result, according to the present invention, it is possible to provide a motor drive circuit in which the drive control circuit can correctly control the motor based on the voltage accurately detected between the terminals of the current detection resistance.
従来の課題を説明するためのグラフである。It is a graph for explaining a conventional problem. 本発明の一実施形態によるモータ駆動回路の概略構成を示すブロック図である。It is a block diagram which shows the schematic structure of the motor drive circuit by one Embodiment of this invention. 本発明の一実施形態によるモータ駆動回路で観測されるモータ消費電流およびモータ回転数の特性を表すグラフである。It is a graph which shows the characteristic of the motor consumption current and the motor rotation speed observed in the motor drive circuit by one Embodiment of this invention. 従来のモータ駆動回路で観測されるモータ消費電流およびモータ回転数の特性を表すグラフである。It is a graph which shows the characteristic of the motor current consumption and the motor rotation speed observed in the conventional motor drive circuit. 従来のモータ駆動回路の概略構成を示すブロック図である。It is a block diagram which shows the schematic structure of the conventional motor drive circuit.
　次に、本発明によるモータ駆動回路を３相ブラシレスモータに適用した場合について、説明する。 Next, a case where the motor drive circuit according to the present invention is applied to a three-phase brushless motor will be described.
　図２は、本発明の一実施形態によるモータ駆動回路１の概略構成を示すブロック図である。 FIG. 2 is a block diagram showing a schematic configuration of a motor drive circuit 1 according to an embodiment of the present invention.
　モータ駆動回路１は、回路基板２に構成され、３相ブラシレスモータ３の各相のモータコイル３ａ，３ｂ，３ｃに接続される。モータ駆動回路１は、各相のモータコイル３ａ，３ｂ，３ｃに対して駆動（ドライバ）回路５ａ，５ｂ，５ｃを備え、制御回路６の制御の下、各モータコイル３ａ，３ｂ，３ｃへ供給する駆動電流ｉを３相ＰＷＭ（Pulse Width Modulation：パルス幅変調）制御する。各ドライバ回路５ａ，５ｂ，５ｃは、それぞれ直列接続されたパワーＭＯＳＦＥＴ（電界効果トランジスタ）４ａ，４ｂおよび電流検出抵抗Ｒで構成される The motor drive circuit 1 is configured on the circuit board 2 and is connected to the motor coils 3a, 3b, 3c of each phase of the three-phase brushless motor 3. The motor drive circuit 1 includes drive (driver) circuits 5a, 5b, 5c for the motor coils 3a, 3b, 3c of each phase, and supplies the motor coils 3a, 3b, 3c under the control of the control circuit 6. The drive current i to be driven is controlled by 3-phase PWM (Pulse Width Modulation). Each driver circuit 5a, 5b, 5c is composed of a power MOSFET (field effect transistor) 4a, 4b and a current detection resistor R connected in series, respectively.
　各ＦＥＴ４ｂのソース端子には電流検出抵抗Ｒが接続され、モータコイル３ａ，３ｂ，３ｃに駆動電流ｉが流れることで、各電流検出抵抗Ｒの端子間には駆動電流ｉに応じた端子間電圧ｖａが生じる。電流検出抵抗Ｒは、抵抗素子でもよいし、回路基板２の表面に導電膜で形成される配線パターンの配線抵抗によって構成されてもよい。本実施形態では電流検出抵抗Ｒの抵抗値を１０[ｍΩ]に設定した。この端子間電圧ｖａは、パッケージングされた駆動（ドライバ）制御ＩＣ（集積化回路）７内に構成される、各差動増幅回路８の一対の入力端子間に入力される。ドライバ制御ＩＣ７内には、差動増幅回路８の他、コンパレータ９、ロジック回路１０、ハイサイドゲートドライバ１１およびローサイドゲートドライバ１２が構成されている。 A current detection resistor R is connected to the source terminal of each FET 4b, and a drive current i flows through the motor coils 3a, 3b, 3c. va occurs. The current detection resistance R may be a resistance element, or may be configured by a wiring resistance of a wiring pattern formed of a conductive film on the surface of the circuit board 2. In this embodiment, the resistance value of the current detection resistor R is set to 10 [mΩ]. This voltage between terminals va is input between a pair of input terminals of each differential amplifier circuit 8 configured in a packaged drive (driver) control IC (integrated circuit) 7. In addition to the differential amplifier circuit 8, the driver control IC 7 includes a comparator 9, a logic circuit 10, a high-side gate driver 11, and a low-side gate driver 12.
　各差動増幅回路８は、入力される電圧ｖａを増幅して電圧Ｖrefとし、増幅した電圧Ｖrefを各コンパレータ９の一方の非反転入力端子に出力する。各コンパレータ９の他方の反転入力端子には所定の基準電圧Ｖｃが与えられている。各コンパレータ９は、差動増幅回路８から入力される電圧Ｖrefが基準電圧Ｖｃよりも高いときはハイレベルの信号をロジック回路１０へ出力し、電圧Ｖrefが基準電圧Ｖｃよりも低いときはローレベルの信号をロジック回路１０へ出力する。 Each differential amplifier circuit 8 amplifies the input voltage va into a voltage Vref, and outputs the amplified voltage Vref to one of the non-inverting input terminals of each comparator 9. A predetermined reference voltage Vc is given to the other inverting input terminal of each comparator 9. Each comparator 9 outputs a high level signal to the logic circuit 10 when the voltage Vref input from the differential amplifier circuit 8 is higher than the reference voltage Vc, and low level when the voltage Vref is lower than the reference voltage Vc. Signal is output to the logic circuit 10.
　ロジック回路１０は、各コンパレータ９の出力に基づいて各ＦＥＴ４ａ，４ｂを制御する。すなわち、コンパレータ９の出力電圧がローレベルのときにはモータ３に電流が流れないように、ハイサイドゲートドライバ１１およびローサイドゲートドライバ１２を制御する。また、コンパレータ９の出力電圧がハイレベルのときにはモータ３に電流が流れるように、ハイサイドゲートドライバ１１およびローサイドゲートドライバ１２を制御する。つまり、ハイサイドゲートドライバ１１は、いずれか１つのドライバ回路５ａ，５ｂ，５ｃを構成するハイサイド側の１つのＦＥＴ４ａのスイッチングをオンする。ローサイドゲートドライバ１２は、他の１つのドライバ回路５ａ，５ｂ，５ｃを構成するローサイド側の１つのＦＥＴ４ｂのスイッチングをオンする。このスイッチングにより、モータに供給される駆動電流ｉは、モータコイル３ａおよび３ｂ、モータコイル３ｃおよび３ｂ、またはモータコイル３ｃおよび３ａを流れるように、ＰＷＭ制御される。 The logic circuit 10 controls each FET 4a and 4b based on the output of each comparator 9. That is, the high-side gate driver 11 and the low-side gate driver 12 are controlled so that no current flows through the motor 3 when the output voltage of the comparator 9 is low level. Further, the high side gate driver 11 and the low side gate driver 12 are controlled so that a current flows through the motor 3 when the output voltage of the comparator 9 is at a high level. That is, the high-side gate driver 11 turns on the switching of one FET 4a on the high-side side constituting any one of the driver circuits 5a, 5b, 5c. The low-side gate driver 12 turns on the switching of one FET 4b on the low-side side that constitutes another driver circuit 5a, 5b, 5c. By this switching, the drive current i supplied to the motor is PWM controlled so as to flow through the motor coils 3a and 3b, the motor coils 3c and 3b, or the motor coils 3c and 3a.
　ここで、ドライバ回路５ａ，５ｂ，５ｃを構成する各ＦＥＴ４ａ，４ｂは、モータ３へ供給する駆動電流ｉをスイッチングするスイッチを構成する。各電流検出抵抗Ｒは、この際、各ＦＥＴ４ａ，４ｂに流れる電流ｉを各ＦＥＴ４ａ，４ｂの近傍で検出する。ドライバ制御ＩＣ７は、電流検出抵抗Ｒの端子間電圧ｖａに基づいて、各ＦＥＴ４ａ，４ｂのスイッチングを上記のように制御する。 Here, each of the FETs 4a and 4b constituting the driver circuits 5a, 5b and 5c constitutes a switch for switching the drive current i supplied to the motor 3. At this time, each current detection resistor R detects the current i flowing through each of the FETs 4a and 4b in the vicinity of each of the FETs 4a and 4b. The driver control IC 7 controls the switching of each of the FETs 4a and 4b as described above based on the voltage between the terminals of the current detection resistor R.
　ドライバ制御ＩＣ７は、グランド端子ピン７ａがその直近にある基準電位パターン１３に接続されることで、グランド端子ピン７ａに接地電位が回路の基準電位Ｖ０として与えられる。各電流検出抵抗Ｒの一端は、配線パターン１４によって各ＦＥＴ４ａ，４ｂから所定の距離をあけて基準電位パターン１３に共通に接続されることで、基準電位Ｖ０に接続される。本実施形態では、各ＦＥＴ４ａ，４ｂおよび電流検出抵抗Ｒが回路基板２におけるドライバ制御ＩＣ７の一方の側に実装され、配線パターン１４の基準電位パターン１３との接続点ｘが、前記一方の側と反対側にあるドライバ制御ＩＣ７のグランド端子ピン７ａに近い位置に置かれることで、所定の距離があけられる。基準電位パターン１３および配線パターン１４は、共に、回路基板２の表面に銅箔等の導電膜がパターニングされて形成されている。 In the driver control IC 7, the ground terminal pin 7a is connected to the reference potential pattern 13 in the immediate vicinity thereof, so that the ground potential is given to the ground terminal pin 7a as the reference potential V0 of the circuit. One end of each current detection resistance R is connected to the reference potential V 0 by being commonly connected to the reference potential pattern 13 at a predetermined distance from the FETs 4a and 4b by the wiring pattern 14. In the present embodiment, the FETs 4a and 4b and the current detection resistance R are mounted on one side of the driver control IC 7 on the circuit board 2, and the connection point x of the wiring pattern 14 with the reference potential pattern 13 is the same as the one side. By placing the driver control IC 7 on the opposite side at a position close to the ground terminal pin 7a of the driver control IC 7, a predetermined distance can be provided. Both the reference potential pattern 13 and the wiring pattern 14 are formed by patterning a conductive film such as a copper foil on the surface of the circuit board 2.
　本実施形態では、配線パターン１４の基準電位パターン１３との接続点ｘと、回路基板２の基板グランド１６との間における回路基板２の基板面に、さらにフェライトビーズインダクタ等のノイズ対策部品１５を備える。基板グランド１６は、回路基板２の例えば裏面の全面に、いわゆるベタパターンとして形成されて、基準電位Ｖ０に保たれる。ノイズ対策部品１５は、問題となるノイズ周波数、例えば、各ＦＥＴ４ａ，４ｂのスイッチング周波数の高調波周波数帯で、ノイズ抑制効果が高くなる部品が選定されるのが、好ましい。 In the present embodiment, a noise suppression component 15 such as a ferrite bead inductor is further provided on the substrate surface of the circuit board 2 between the connection point x of the wiring pattern 14 with the reference potential pattern 13 and the substrate ground 16 of the circuit board 2. Be prepared. The substrate ground 16 is formed as a so-called solid pattern on the entire surface of the back surface of the circuit board 2 , for example, and is maintained at a reference potential of V0. As the noise suppression component 15, it is preferable to select a component having a high noise suppression effect in the harmonic frequency band of the noise frequency in question, for example, the switching frequency of each of the FETs 4a and 4b.
　図３に示すグラフは、上記の本実施形態によるモータ駆動回路１で駆動されるモータ３の消費電流と回転数とを観測した結果を示す。同グラフの横軸は時間[ｍｓｅｃ]、右側の縦軸はモータ消費電流[ｍＡ]、左側の縦軸はモータ回転数[ｒｐｍ]を表す。また、細かく振幅する特性線２１はモータ消費電流、矩形状に大きく振幅する特性線２２はモータ回転数の特性を表す。これらモータ消費電流およびモータ回転数は、制御回路６を構成するＩＣのテストピンコネクタにケーブルを接続し、そのケーブルを外部のパーソナルコンピュータ（ＰＣ）に接続して、制御回路６を構成するＩＣ内部の各時点での特性値を表すカウンタ機能を利用することで、観測した。また、制御回路６の設定により、モータ３の回転が正回転を１．５秒間維持し、その後負回転を１．５秒間維持して、正回転および負回転が時間的に連続する動作モードに設定した。また、モータ３の回転数は正回転および負回転共に５００～５５０[ｒｐｍ]に設定した。 The graph shown in FIG. 3 shows the results of observing the current consumption and the rotation speed of the motor 3 driven by the motor drive circuit 1 according to the above embodiment. The horizontal axis of the graph represents time [msec], the vertical axis on the right side represents motor current consumption [mA], and the vertical axis on the left side represents motor rotation speed [rpm]. Further, the characteristic line 21 that oscillates finely represents the current consumption of the motor, and the characteristic line 22 that oscillates greatly in a rectangular shape represents the characteristics of the motor rotation speed. For these motor current consumption and motor rotation speed, connect a cable to the test pin connector of the IC that constitutes the control circuit 6, connect the cable to an external personal computer (PC), and inside the IC that constitutes the control circuit 6. It was observed by using the counter function that shows the characteristic value at each time point. Further, by setting the control circuit 6, the rotation of the motor 3 maintains the positive rotation for 1.5 seconds, and then the negative rotation is maintained for 1.5 seconds, so that the operation mode in which the positive rotation and the negative rotation are continuous in time is set. I set it. Further, the rotation speed of the motor 3 was set to 500 to 550 [rpm] for both forward rotation and negative rotation.
　また、図４に示すグラフは、従来のモータ駆動回路で同様にして観測されるモータ３の消費電流と回転数とを観測した結果を示す。図５に示すように、従来のモータ駆動回路１７では、電流検出抵抗Ｒが、モータ駆動電流をスイッチングする各ＦＥＴ４ａ，４ｂおよび基準電位となる基板グランド１６に近接する位置で、それらの間に接続されている。なお、同図において図２と同一または相当する部分には同一符号を付してその説明は省略する。図４に示すグラフの横軸及び各縦軸は図３に示すグラフと同様である。また、細かく振幅する特性線３１はモータ消費電流、矩形状に大きく振幅する特性線３２はモータ回転数の特性を表す。 Further, the graph shown in FIG. 4 shows the results of observing the current consumption and the rotation speed of the motor 3 similarly observed in the conventional motor drive circuit. As shown in FIG. 5, in the conventional motor drive circuit 17, the current detection resistance R is connected between the FETs 4a and 4b for switching the motor drive current and the substrate ground 16 which is the reference potential at a position close to them. Has been done. In the figure, the same or corresponding parts as those in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted. The horizontal axis and each vertical axis of the graph shown in FIG. 4 are the same as the graph shown in FIG. Further, the characteristic line 31 that oscillates finely represents the motor consumption current, and the characteristic line 32 that oscillates greatly in a rectangular shape represents the characteristics of the motor rotation speed.
　図３および図４に示すグラフを比較すると分かるように、従来のモータ消費電流の特性線３１は本実施形態の特性線２１と比較して全時間帯にわたって振幅が大きくなっており、従来のモータ駆動回路１７では、モータ消費電流に各ＦＥＴ４ａ，４ｂのスイッチングノイズが全時間帯にわたって重畳していることが理解される。このスイッチングノイズにより、電流検出抵抗Ｒの一端が接続される基板グランド１６の基準電位Ｖ０が図１（ｂ）に示すように変動する。 As can be seen by comparing the graphs shown in FIGS. 3 and 4, the characteristic line 31 of the conventional motor consumption current has a larger amplitude over the entire time zone as compared with the characteristic line 21 of the present embodiment, and the conventional motor has a larger amplitude. In the drive circuit 17, it is understood that the switching noise of each of the FETs 4a and 4b is superimposed on the motor current consumption over the entire time zone. Due to this switching noise, the reference potential V 0 of the substrate ground 16 to which one end of the current detection resistor R is connected fluctuates as shown in FIG. 1 (b).
　これは、モータ３へ供給される駆動電流が各ＦＥＴ４ａ，４ｂによってスイッチングされることで、スイッチングノイズが、各ＦＥＴ４ａ，４ｂから電流検出抵抗Ｒおよび配線パターンを伝って、基板グランド１６に伝導するためと、考えられる。また、同時に、スイッチングノイズが、各ＦＥＴ４ａ，４ｂから空間に放出されて、基板グランド１６に伝搬するためと、考えられる。基板グランド１６の基準電位Ｖ０のこの変動により、差動増幅回路８に与えられる電圧Ｖａが、基準電位Ｖ０に対して所定のしきい値電圧（例えば２[Ｖ]）を満たさない電圧（例えば１．８[Ｖ]）になると、コンパレータ９の出力をロジック回路１０が判別できなくなる。したがって、ロジック回路１０は、差動増幅回路８に与えられる電圧Ｖａが所定のしきい値電圧になるまでモータ３の回転を待機させる。 This is because the drive current supplied to the motor 3 is switched by each of the FETs 4a and 4b, so that the switching noise is transmitted from each of the FETs 4a and 4b to the substrate ground 16 through the current detection resistor R and the wiring pattern. it is conceivable that. At the same time, it is considered that the switching noise is emitted from each of the FETs 4a and 4b into the space and propagates to the substrate ground 16. Due to this fluctuation of the reference potential V 0 of the substrate ground 16, the voltage Va applied to the differential amplifier circuit 8 does not satisfy a predetermined threshold voltage (for example, 2 [V]) with respect to the reference potential V 0 (for example, 2 [V]). For example, when it becomes 1.8 [V]), the logic circuit 10 cannot discriminate the output of the comparator 9. Therefore, the logic circuit 10 waits for the rotation of the motor 3 until the voltage Va applied to the differential amplifier circuit 8 reaches a predetermined threshold voltage.
　このため、従来のモータ回転数の特性線３２は、例えば、図４に破線の楕円Ａで示す箇所において、モータ回転数が略０になる時間帯が生じ、モータ３に電流は流れているが、モータ３が回転していない待機時間が発生する。この結果、モータ３は、正回転または負回転に連続的にスムーズに回転が移行しなくなる。なお、モータ３の正回転時にはモータ消費電流は正の電流となり、負回転時には負の電流が観測される。 Therefore, in the conventional characteristic line 32 of the motor rotation speed, for example, at the position indicated by the ellipse A of the broken line in FIG. 4, there is a time zone in which the motor rotation speed becomes substantially 0, and a current is flowing through the motor 3. , There is a waiting time when the motor 3 is not rotating. As a result, the motor 3 does not continuously and smoothly shift to forward rotation or negative rotation. When the motor 3 rotates in the forward direction, the current consumed by the motor becomes a positive current, and when the motor 3 rotates in the negative direction, a negative current is observed.
　これに対して、電流検出抵抗Ｒの一端が配線パターン１４を介して所定の距離をあけて基準電位パターン１３との接続点ｘに接続される、本実施形態のモータ駆動回路１では、図３のモータ回転数の特性線２２に示されるように、モータ回転数が略０になる時間帯は生じず、モータ３は、正回転または負回転に連続的にスムーズに回転が移行するのが観測される。 On the other hand, in the motor drive circuit 1 of the present embodiment, one end of the current detection resistor R is connected to the connection point x with the reference potential pattern 13 at a predetermined distance via the wiring pattern 14, FIG. As shown in the characteristic line 22 of the motor rotation speed of, there is no time zone when the motor rotation speed becomes almost 0, and it is observed that the rotation of the motor 3 continuously and smoothly shifts to positive rotation or negative rotation. Will be done.
　本実施形態によるモータ駆動回路１では、モータ３へ供給される駆動電流が各ＦＥＴ４ａ，４ｂによってスイッチングされることで、スイッチングノイズが、各ＦＥＴ４ａ，４ｂから電流検出抵抗Ｒおよび配線パターン１４を伝って、配線パターン１４の基準電位パターン１３との接続点ｘまで伝導する。また、スイッチングノイズは、各ＦＥＴ４ａ，４ｂから空間に放出されて、配線パターン１４の基準電位パターン１３との接続点ｘにまで飛来する。 In the motor drive circuit 1 according to the present embodiment, the drive current supplied to the motor 3 is switched by the FETs 4a and 4b, so that the switching noise is transmitted from the FETs 4a and 4b through the current detection resistance R and the wiring pattern 14. , Conducts to the connection point x of the wiring pattern 14 with the reference potential pattern 13. Further, the switching noise is emitted from each of the FETs 4a and 4b into the space and flies to the connection point x of the wiring pattern 14 with the reference potential pattern 13.
　しかし、本実施形態によるモータ駆動回路１によれば、電流検出抵抗Ｒの一端は、配線パターン１４によって各ＦＥＴ４ａ，４ｂから所定の距離をあけて基準電位パターン１３に接続されて、基準電位Ｖ０が与えられる。本実施形態では、各ＦＥＴ４ａ，４ｂと、配線パターン１４の基準電位パターン１３との接続点ｘとの間の距離は、それらが、ドライバ制御ＩＣ７の両側に配置されることで、所定の距離があけられる。 However, according to the motor drive circuit 1 according to the present embodiment, one end of the current detection resistor R is connected to the reference potential pattern 13 at a predetermined distance from each of the FETs 4a and 4b by the wiring pattern 14, and the reference potential V0 . Is given. In the present embodiment, the distance between each of the FETs 4a and 4b and the connection point x between the reference potential pattern 13 of the wiring pattern 14 is set to a predetermined distance by arranging them on both sides of the driver control IC 7. Can be opened.
　したがって、配線パターン１４を伝導するスイッチングノイズは、配線パターン１４を伝って基準電位パターン１３との接続点ｘに至る間に減衰する。また、空間を伝搬するスイッチングノイズは、空間を飛んで配線パターン１４の基準電位パターン１３との接続点ｘに到達するまでに、減衰する。このため、配線パターン１４の基準電位パターン１３との接続点ｘにおいて、基準電位Ｖ０は、スイッチングノイズの影響を受け難くなり、ほぼ一定に保たれるようになる。この結果、各差動増幅回路８の入力電圧にスイッチングノイズが重畳しなくなり、モータ駆動回路１のドライバ制御ＩＣ７は、電流検出抵抗Ｒの端子間に正確に検出される電圧ｖａに基づいて、正しくモータ３を制御することができるようになる。 Therefore, the switching noise conducted through the wiring pattern 14 is attenuated while being transmitted through the wiring pattern 14 and reaching the connection point x with the reference potential pattern 13. Further, the switching noise propagating in the space is attenuated by the time it flies through the space and reaches the connection point x with the reference potential pattern 13 of the wiring pattern 14. Therefore, at the connection point x of the wiring pattern 14 with the reference potential pattern 13, the reference potential V 0 is less likely to be affected by the switching noise and is kept substantially constant. As a result, switching noise does not overlap with the input voltage of each differential amplifier circuit 8, and the driver control IC 7 of the motor drive circuit 1 correctly detects the voltage va between the terminals of the current detection resistance R. The motor 3 can be controlled.
　また、本実施形態によるモータ駆動回路１によれば、配線パターン１４の基準電位パターン１３との接続点ｘまで配線パターン１４を伝導する最中に減衰しきれなかったスイッチングノイズ、および、その接続点ｘまで空間を伝搬する最中に減衰しきれなかったスイッチングノイズは、ノイズ対策部品１５によってさらに減衰される。このため、基板グランド１６に伝導または結合するノイズの流入が抑制され、電流検出抵抗Ｒの一端に与えられる基準電位Ｖ０は、スイッチングノイズの影響をさらに受け難くなり、ほとんど一定に保たれるようになる。この結果、モータ駆動回路１のドライバ制御ＩＣ７は、電流検出抵抗Ｒの端子間により正確に検出される電圧ｖａに基づいて、より正しくモータ３を制御することができるようになる。 Further, according to the motor drive circuit 1 according to the present embodiment, the switching noise that could not be completely attenuated while conducting the wiring pattern 14 to the connection point x of the reference potential pattern 13 of the wiring pattern 14 and the connection point thereof. The switching noise that could not be completely attenuated while propagating in space up to x is further attenuated by the noise suppression component 15. Therefore, the inflow of noise conducted or coupled to the substrate ground 16 is suppressed, and the reference potential V 0 given to one end of the current detection resistor R is further less affected by the switching noise and is kept almost constant. become. As a result, the driver control IC 7 of the motor drive circuit 1 can control the motor 3 more accurately based on the voltage va accurately detected between the terminals of the current detection resistance R.
　上記実施形態の説明では、モータ３が３相のブラシレスモータである場合について説明したが、単相や２相のブラシレスモータのモータ駆動回路にも同様に適用することができる。また、Ｈブリッジ回路を使った各相数のブラシ付きモータ等のモータ駆動回路にも同様に適用することができる。また、モータ３は必ずしも正転および逆転する必要はなく、モータコイル３ａ，３ｂ，３ｃの回転がスイッチのスイッチングによって回転および停止する等して制御されるモータのモータ駆動回路にも同様に適用することができる。そして、これらの各場合においても上記の実施形態と同様な作用効果が奏される。 In the description of the above embodiment, the case where the motor 3 is a three-phase brushless motor has been described, but the same can be applied to a motor drive circuit of a single-phase or two-phase brushless motor. Further, it can be similarly applied to a motor drive circuit such as a brushed motor having each phase using an H-bridge circuit. Further, the motor 3 does not necessarily have to rotate in the forward and reverse directions, and is similarly applied to the motor drive circuit of the motor in which the rotation of the motor coils 3a, 3b, and 3c is controlled by rotating and stopping by switching of the switch. be able to. And, in each of these cases, the same action and effect as those of the above-described embodiment are exhibited.
　１…モータ駆動回路
　２…回路基板
　３…モータ
　３ａ，３ｂ，３ｃ…モータコイル
　４ａ，４ｂ…パワーＭＯＳＦＥＴ（スイッチ）
　５ａ，５ｂ，５ｃ…駆動回路
　６…制御回路
　７…駆動制御ＩＣ（駆動制御回路）
　８…差動増幅回路
　９…コンパレータ
　１０…ロジック回路
　１１…ハイサイドゲートドライバ
　１２…ローサイドゲートドライバ
　１３…基準電位パターン
　１４…配線パターン
　１５…ノイズ対策部品（フェライトビーズインダクタ）
　１６…基板グランド
　ｘ…配線パターン１４の基準電位パターン１３との接続点 1 ... Motor drive circuit 2 ... Circuit board 3 ... Motor 3a, 3b, 3c ... Motor coil 4a, 4b ... Power MOSFET (switch)
5a, 5b, 5c ... Drive circuit 6 ... Control circuit 7 ... Drive control IC (drive control circuit)
8 ... Differential amplifier circuit 9 ... Comparator 10 ... Logic circuit 11 ... High side gate driver 12 ... Low side gate driver 13 ... Reference potential pattern 14 ... Wiring pattern 15 ... Noise countermeasure parts (ferrite bead inductor)
16 ... Substrate ground x ... Connection point of wiring pattern 14 with reference potential pattern 13

Claims (4)

  1. 　モータへ供給する駆動電流をスイッチングするスイッチと、
    　前記スイッチに流れる電流を前記スイッチの近傍で検出する一端が基準電位に接続される電流検出抵抗と、
    　前記電流検出抵抗の端子間電圧に基づいて前記スイッチのスイッチングを制御する駆動制御回路と、
    　前記駆動制御回路に基準電位を与える基準電位パターンと、
    　前記電流検出抵抗の前記一端を前記スイッチから所定の距離をあけて前記基準電位パターンに接続する配線パターンと
    　を回路基板に備えるモータ駆動回路。     A switch that switches the drive current supplied to the motor,
    A current detection resistor with one end connected to a reference potential that detects the current flowing through the switch in the vicinity of the switch.
    A drive control circuit that controls switching of the switch based on the voltage between the terminals of the current detection resistor.
    A reference potential pattern that gives a reference potential to the drive control circuit,
    A motor drive circuit provided on a circuit board with a wiring pattern in which one end of the current detection resistor is connected to the reference potential pattern at a predetermined distance from the switch.
  2. 　前記配線パターンの前記基準電位パターンとの接続点と前記回路基板の基板グランドとの間にさらにノイズ対策部品を備えることを特徴とする請求項１に記載のモータ駆動回路。 The motor drive circuit according to claim 1, further comprising a noise suppression component between the connection point of the wiring pattern with the reference potential pattern and the substrate ground of the circuit board.
  3. 　前記駆動制御回路はパッケージングされたＩＣとして構成され、
    　前記スイッチおよび前記電流検出抵抗は前記回路基板における前記ＩＣの一方の側に実装され、
    　前記配線パターンの前記基準電位パターンとの接続点は、前記駆動制御回路に基準電位を与える前記一方の側と反対側にある前記ＩＣの端子に近い位置に置かれることを特徴とする請求項１または請求項２に記載のモータ駆動回路。     The drive control circuit is configured as a packaged IC.
    The switch and the current detection resistor are mounted on one side of the IC on the circuit board.
    Claim 1 is characterized in that the connection point of the wiring pattern with the reference potential pattern is placed at a position close to the terminal of the IC on the side opposite to the one side that gives the reference potential to the drive control circuit. Alternatively, the motor drive circuit according to claim 2.
  4. 　前記駆動制御回路は、
    　前記電流検出抵抗の端子間電圧が入力端子間に入力される差動増幅回路と、
    　前記差動増幅回路の出力が一方の入力端子に入力され他方の入力端子に基準電圧が与えられるコンパレータと、
    　前記コンパレータの出力に基づいて前記スイッチを制御するロジック回路とを備えて構成される
    　ことを特徴とする請求項１から請求項３のいずれか１項に記載のモータ駆動回路。     The drive control circuit
    A differential amplifier circuit in which the voltage between the terminals of the current detection resistor is input between the input terminals,
    A comparator in which the output of the differential amplifier circuit is input to one input terminal and a reference voltage is given to the other input terminal.
    The motor drive circuit according to any one of claims 1 to 3, further comprising a logic circuit for controlling the switch based on the output of the comparator.
PCT/JP2021/040467 2020-11-26 2021-11-02 Motor driving circuit WO2022113673A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004304926A (en) * 2003-03-31 2004-10-28 Toshiba Corp Motor drive circuit arrangement for laundry equipment
JP2015136277A (en) * 2014-01-20 2015-07-27 セイコーエプソン株式会社 Circuit device, circuit board and electronic apparatus
JP2020188660A (en) * 2019-05-17 2020-11-19 株式会社デンソー Electric power conversion device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004304926A (en) * 2003-03-31 2004-10-28 Toshiba Corp Motor drive circuit arrangement for laundry equipment
JP2015136277A (en) * 2014-01-20 2015-07-27 セイコーエプソン株式会社 Circuit device, circuit board and electronic apparatus
JP2020188660A (en) * 2019-05-17 2020-11-19 株式会社デンソー Electric power conversion device

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