Motor driver, switched mode power converter and system

Abstract

A motor driver is coupled to an auxiliary power supply and to a motor having a winding. The motor driver includes a switching circuit having an auxiliary node coupled to the auxiliary power supply and a winding node coupled to the winding. The switching circuit is configured to store energy in an inductance of a motor winding and to deliver energy to an auxiliary power source. To store energy, the switching circuit and the winding are coupled to establish a current in the winding. To deliver energy, the switching circuit delivers the current in the winding to the auxiliary node.

Description

Technical Field

[0001] The utility model generally relates to an auxiliary power supply used with a motor drive. Background Art

[0002] Motor drive inverters (eg, half-bridge motor driver circuits) typically use an auxiliary power supply to generate a source of power for the power transistor drivers and the microprocessor that controls the operation of the motor.

[0003] Some half-bridge motor driver circuits include a self-starting feature that can support operation of these circuits indefinitely by using a high voltage (HV) direct current (dc) linear regulator that draws power from the same HV bus that provides power to the motor. However, even though the half-bridge motor driver circuit can power itself, the additional power used by the system microcontroller (MCU) and other circuits often results in excessive power dissipation from the linear regulator.

[0004] One previous solution is to have an auxiliary switching power supply, usually a buck converter or a flyback converter, which efficiently derives power for the motor drive inverter directly from the high voltage bus through a dedicated inductive energy transfer element. This auxiliary power supply comes at the expense of additional cost and space consumption on the circuit board. Utility Model Content

[0005] The utility model provides the following technical solutions.

[0006] A motor driver for coupling to an auxiliary power supply and to a winding of a motor, the motor driver comprising: a control circuit coupled to a switch circuit to switch the switch circuit to receive current and switch the switch circuit to deliver current, wherein the motor driver further comprises the switch circuit having an auxiliary node coupled to the auxiliary power supply and a winding node coupled to the winding, the switch circuit being coupled to receive current and store energy in the inductance of the winding and deliver current to the auxiliary power supply. In one embodiment, the switch circuit comprises: an upper switch coupled to the winding node and to the auxiliary node; and a lower switch coupled to the auxiliary node and to a reference ground. In one embodiment, the upper switch and the lower switch comprise a common source and common gate configuration of a normally-on transistor and a normally-off transistor.

[0007] A system includes: a switch of a first motor driver, the switch being coupled to a power supply rail; a motor having a winding coupled to the switch; a second motor driver having a winding node coupled to the winding to receive current from the power supply rail, wherein: the second motor driver has an auxiliary node to deliver current; and the system includes an auxiliary power supply coupled to the auxiliary node of the second motor driver. In one embodiment, the second motor driver includes: a control circuit coupled to send a control signal indicating when to deliver current; and a switch circuit coupled to the winding node, the switch circuit having an auxiliary node coupled to the auxiliary power supply, the switch circuit also coupled to receive the control signal and generate an enable signal, the switch circuit including: an upper switch coupled to the winding node and to the auxiliary node, and a lower switch coupled to the auxiliary node and to a reference ground.

[0008] A switch mode power converter comprises: an inductive energy transfer element having a first end and a second end, wherein: the inductive energy transfer element comprises a winding of a motor; the switch mode power converter further comprises a switch circuit having an auxiliary node, the switch circuit being coupled to the first end of the winding and coupled to a reference ground; and a drive circuit comprising the switch circuit, the drive circuit being configured to receive a control signal indicating when to store energy in the inductance of the winding and when to deliver energy to the auxiliary node.

[0009] A system comprises: a half bridge, the half bridge comprising a high side switch, a high side drive circuit, the high side drive circuit being coupled to the high side switch of the half bridge; a system controller, the system controller being coupled to provide control signals to the high side drive circuit and the low side drive circuit; wherein: the half bridge further comprises a composite low side switch, the composite low side switch being coupled in series with the high side switch to define a winding node therebetween, wherein the composite low side switch comprises an upper low side switch and a lower low side switch, the upper low side switch and the lower low side switch being coupled in series to define an auxiliary node therebetween; and the system further comprises the low side drive circuit, the low side drive circuit being coupled to the composite low side switch of the half bridge, and an auxiliary power supply, the auxiliary power supply being coupled to supply power to the system controller, wherein the auxiliary power supply is also coupled to receive power from the auxiliary node defined between the upper low side switch and the lower low side switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.

[0011] Figure 1 is a functional block diagram illustrating an auxiliary power supply in a motor drive system including a half-bridge motor driver circuit according to an embodiment of the present disclosure.

[0012] Figure 2 is a functional block diagram illustrating a current path for an auxiliary power supply in a switch-mode power converter according to an embodiment of the present disclosure.

[0013] Figure 3 is a timing diagram illustrating the operation of an embodiment for obtaining current from motor windings.

[0014] Figure 4 is a timing diagram illustrating the operation of an additional embodiment for obtaining current from the motor windings.

[0015] Figure 5 is a timing diagram illustrating the operation of an additional embodiment for obtaining current from the motor windings.

[0016] Figure 6 is a timing diagram illustrating the operation of an additional embodiment for obtaining current from the motor windings.

[0017] Figure 7 is a timing diagram illustrating the operation of an additional embodiment for obtaining current from the motor windings.

[0018] Figure 8 is a timing diagram illustrating the operation of an additional embodiment for obtaining current from the motor windings.

[0019] Fig. 9 is used for Figure 1 A circuit schematic diagram of an embodiment of a portion of a half-bridge motor driver circuit is shown in FIG.

[0020] Fig.10 is used for Figure 1 A circuit schematic diagram of an embodiment of a portion of a half-bridge motor driver circuit is shown in FIG.

[0021] Fig.11 Illustrated Figure 1 0047 is a circuit schematic diagram of an embodiment of a half-bridge motor driver circuit including a portion of an auxiliary switch for an auxiliary power supply.

[0022] Fig.12 Illustrated Figure 1Another circuit schematic diagram of an embodiment of a portion of a half-bridge motor driver circuit including an auxiliary switch for an auxiliary power supply is shown in FIG.

[0023] Fig.13 It is an example based on Fig.12 0047 is a timing diagram of the operation of the embodiment shown in 0047 for obtaining current from the motor windings.

[0024] Fig.14A , Fig. 14B and Fig. 14C Illustrated Figure 1 Additional embodiments of the system shown in .

[0025] Fig.15 is a functional block diagram of another embodiment according to the present disclosure.

[0026] Fig.16 is a process flow diagram according to an embodiment of the present disclosure.

[0027] In all several views of the accompanying drawings, corresponding reference numerals indicate corresponding parts. It will be appreciated by the skilled person that the elements in the accompanying drawings are illustrated for simplicity and clarity and are not necessarily drawn to scale. For example, the sizes of some elements in the accompanying drawings may be exaggerated relative to other elements to help improve the understanding of various embodiments of the utility model. In addition, common but easily understood elements that are useful or necessary in commercially feasible embodiments are generally not depicted so as to less hinder the viewing of these various embodiments of the utility model. DETAILED DESCRIPTION

[0028] In the following description, many specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that specific details are not required to practice the present invention. In other cases, well-known materials or methods are not described in detail to avoid obscuring the present invention.

[0029] Reference throughout this specification to "one embodiment", "anembodiment", "one example" or "an example" means that the specific features, structures or characteristics described in conjunction with the embodiment or example are included in at least one embodiment of the present utility model. Therefore, the phrases "in one embodiment", "in an embodiment", "one example" or "an example" appearing in various places throughout this specification do not necessarily all refer to the same embodiment or example. In addition, specific features, structures or characteristics may be combined in any suitable combination and / or sub-combination in one or more embodiments or examples. Specific features, structures or characteristics may be included in integrated circuits, electronic circuits, combinational logic circuits, or other suitable components that provide the described functions. In addition, it should be understood that the drawings provided herewith are used for the purpose of explanation to those of ordinary skill in the art, and the drawings are not necessarily drawn to scale.

[0030] A motor drive inverter (e.g., a configuration of one or more half-bridge motor driver circuits) may include a control circuit that may be coupled to a motor winding having a winding inductance via a switching circuit. In a first state, the switching circuit is configured to obtain current from a high voltage power source that powers the motor and store energy in the winding in the form of a current in the inductance of the winding. In a second state, the switching circuit is further configured to deliver the stored energy to the auxiliary power supply by switching, delivering or diverting the current in the winding to the input of the auxiliary power supply. The first state and the second state are based on operating parameters of the auxiliary power supply, the motor, and the motor drive inverter. The operating parameters may include a duty cycle (the ratio of the time when the switch is in the first state to the total time: the total time of the time in the first state plus the time in the second state), the current in the winding, and the need for the auxiliary power supply to provide a regulated output voltage for the input current. The motor driver circuit may be housed in one or more electronic packages so that they may be used as part of a printed circuit board circuit. The control circuit may be housed in the same electronic package as the motor driver circuit or as a separate circuit housed in one or more other electronic packages. The control circuitry may include circuitry such as a microcontroller unit (MCU) that may be programmed to provide electronic signals to the motor driver circuits to control the current flow in the motor windings to which they are coupled.

[0031] The inherent inductance of the motor windings is used as an energy storage element to perform power conversion from a high voltage dc bus to a significantly lower voltage at the input of the auxiliary power supply. In one embodiment, the existing inverter power transistors can be used as switching transistors to provide current to the auxiliary power supply. Therefore, the switching power conversion for the auxiliary power supply reuses the existing circuits for the operation of the motor inverter and avoids the unacceptable power dissipation that may occur using a linear regulator. In addition, using the inductance of the motor windings eliminates the need for a dedicated inductive energy transfer element in the auxiliary power supply that is directly operated by the high voltage bus. In other words, the switches of the motor inverter can be switches in a switch-mode power converter having an inductive energy transfer element that is also a winding of the motor. The input of the switch-mode power converter can be a high voltage input source for the motor, and the output of the switch-mode power converter can be the input of the auxiliary power supply.

[0032] The present invention can use existing inverter power switches, such as field effect transistors (FETs), insulated gate bipolar transistors (IGBTs), and enhancement mode gallium nitride transistors (GaN), for switching circuits. Another embodiment uses a cascode power switch comprising a high-voltage normally-on transistor coupled to a low voltage (LV) cascode FET, such as a normally-on GaN transistor, a silicon carbide (SiC) transistor, or a junction field effect transistor (JFET). In this configuration, the low-voltage FET is turned off by the controller during a standard switching cycle to temporarily deliver current from the motor winding to the input of an auxiliary power supply. Therefore, the switching circuit can be used to power both a driver integrated circuit (IC) and an auxiliary circuit such as a system microcontroller (MCU) during normal motor operation or when the motor is stationary.

[0033] When the motor is stationary, some of the inverter switches can be turned on for a short time to provide current for a relatively low-power auxiliary power supply to power the auxiliary circuit. For illustrative purposes, the short time is less than the time normally used to run the motor. The auxiliary circuit may include a power switch driver, a system MCU and an IC. For illustrative purposes, the power of the system MCU IC in standby will typically be between 3 milliwatts and 10 milliwatts. The motor winding current generated during any switching cycle can be controlled to have a sufficiently low value so that a negligible force is generated to limit the movement of the motor. In addition, the frequency of the switch will be limited so that the motor inertia, friction and load can also minimize the operation of the motor.

[0034] When the motor is in motion, some of the inverter switches can be turned off for a relatively short time within a typical inverter switching cycle to provide current for a relatively low power auxiliary power supply to power the auxiliary circuits. The motor winding current can be controlled to increase the current in the winding above a value that causes the motor to move. In addition, the frequency of the switching can be limited until there is enough current to produce the movement of the motor and still provide current to the auxiliary power supply.

[0035] Figure 1 is a functional block diagram of an embodiment of the present disclosure, shown at 10. The windings of the motor 14 are coupled to three half-bridge motor driver circuits 12 1 , 12 2 and 12 3 . Half-bridge motor driver circuit 12 1 , 12 2 and 12 3 Each of the half-bridge motor driver circuits 12 is coupled between VDD (typically a high voltage dc source) and a reference ground and may also be coupled to an auxiliary power supply. 1 is shown coupled to an auxiliary power source 16. The motor drive 12 1 The circuits in the circuits can be collectively referred to as switch circuits. The system MCU 18 is configured to drive the high side (HS) drive circuits of the half-bridge motor driver circuit, such as 20 1 and to the low side (LS) drive circuit such as 22 1 Control signals CB1, CB2, CB3 are provided. It should be understood that each signal, CB1, CB2 and CB3, may include two or more signal lines in a real motor inverter drive and are therefore labeled as signal buses. MCU 18 is an embodiment of the control circuit discussed above, which is Figure 1 The embodiment is shown as a motor drive 12 1 It should be understood that in other embodiments, the control circuit 18 can be integrated into the motor driver 12 1 , 12 2 or 12 3 One of the inside.

[0036] Half-bridge motor driver circuit 12 1 Includes diode 26 1 Parallel high-side (HS) switches 24 1 HS switch 24 1 Coupled to VDD and coupled to the windings of the motor 14. HS switch 24 1 is configured to be driven by a high-side (HS) driver circuit 20 1Drive. Upper low side (ULS) switch 28 1 With ULS diode 30 1 Parallel. ULS switch 28 1 At winding node 38 1 is coupled to the windings of the motor 14 and at an auxiliary (AUX) node 36 1 The lower lowside (LLS) switch 32 is coupled to the auxiliary power supply 16. 1 With LLS diode 34 1 Parallel. LLS switch 32 1 is coupled to the AUX node 36 1 Between the reference ground. ULS switch 28 1 and LLS switch 32 1 Both are configured to be driven by LS circuit 22 1 The auxiliary power supply 16 is coupled to the AUX node 36 1 and a reference ground. Embodiments of the auxiliary power supply include a low voltage switch mode power supply and a linear regulated power supply.

[0037] use Figure 1 The windings of the motor 14 are coupled to two half-bridge motor driver circuits 12 1 , 12 2 The operation of energy storage and current delivery is illustratively described in the embodiment of FIG. Two half-bridge motor driver circuits 12 1 , 12 2 is used to conduct current that can store energy in the windings of the motor 14 and deliver the current to the auxiliary power supply 16. Each half-bridge motor driver circuit 12 1 , 12 2 The respective switching circuits are configured in response to receiving their corresponding control signals CB1, CB2 sent by the system MCU 18. The switching signals within the half-bridge motor driver circuit indicate when to increase or decrease the current in the winding and when to increase or decrease the current I W A portion of the AUX node 36 1 Delivered to auxiliary power source 16.

[0038] It will be appreciated that in a typical motor the windings of the motor 14 may be comprised of several windings, often referred to as phase windings of the motor, but are combined into a single winding for simplicity in this description.

[0039] To increase the current in the winding, a first end 14 of the winding of the motor 14 is connected. VDD Half-bridge motor driver circuit 12 2The HS switch (not shown) in the embodiment is closed. A closed switch can conduct current, while an open switch conducts negligible current. At the second end 14 coupled to the auxiliary power source 16 and coupled to the winding of the motor 14 AUX Half-bridge motor driver circuit 12 1 , the HS switch can be disconnected and the ULS switch 28 1 and LLS switch 32 1 It can be closed and opened in an appropriate manner to drive the motor and provide current to the auxiliary power supply.

[0040] For the second end of the winding 14 AUX Half-bridge motor driver circuit 12 1 , in order to establish the current I in the winding W , HS switch 24 1 can be disconnected and switched ULS28 1 and LLS 32 1 can be closed. Then, in order to reduce the current I W Delivered to auxiliary power supply 16, HS switch 24 1 can remain disconnected while the ULS switch 28 1 The LLS switch 32 may remain closed and 1 Can be disconnected.

[0041] Figure 2 is a functional block diagram showing the current path for the auxiliary power supply in a switch mode power converter 60, shown at 58, according to an embodiment of the present disclosure. The switch mode power converter 60 is coupled between VDD and a reference ground, and is also coupled to the auxiliary power supply 16 and the system MCU 18. The switch mode power converter is a dc-dc converter that stores energy from a high voltage input VDD and delivers the energy at a lower voltage to the input of the auxiliary power supply.

[0042] Figure 2 The switch mode power converter 60 in the embodiment of the present invention includes the windings of the motor 14, the half-bridge motor driver circuit 12 2 High-side circuit and half-bridge motor driver circuit 12 1 The low side circuit.

[0043] Half-bridge motor driver circuit 12 2 The high side circuit includes a diode 26 2 HS switches in parallel 24 2 and HS drive circuit 20 2 HS switch 24 2 It is also coupled to VDD and to the windings of motor 14 .

[0044] Half-bridge motor driver circuit 12 1 The low side circuit consists of a 30 1 Parallel ULS switches 28 1 , and LLS diode 34 1 Parallel LLS switches 32 1 And LS drive circuit 22 1 .

[0045] The system MCU 18 is configured to provide the LS drive circuit 22 with 1 Provides signal CB1 and HS driving circuit 20 2 A signal CB2 is provided.

[0046] In operation, the windings of the motor 14 may be coupled to the HS switch 24 2 and ULS switch 28 1 The switching circuit conducts current that can store energy in the windings of the motor 14 and can deliver a portion of the energy in the form of current to the auxiliary power supply. The switching circuit responds to control signals CB1 , CB2 sent by the system MCU 18 .

[0047] Half-bridge motor driver circuit 12 1 LS drive circuit 22 1 In response to the control signal CB1, the HS driving circuit 20 2 The control signals CB1 and CB2 can be responded to by the system MCU 18 according to Figures 3 to 7 A transmission in the timing diagram disclosed in . Figure 2 As shown in the figure, in the winding 14 VDD Half-bridge motor driver circuit 12 at the end 2 HS switch 24 2 In its HS drive circuit 20 2 When receiving the driving signal, the current I W Delivered to the winding. Combined, the 14 AUX Half-bridge motor driver circuit 12 at the end 1 ULS Switch 28 1 and LLS switch 32 1 can be switched appropriately to increase and decrease the current in the winding and to divide the current I W A portion of the power is delivered from the AUX node 36 to the auxiliary power source 16 when the auxiliary power source 16 requests it.

[0048] Figures 3 to 8 is an example for Figure 2 The motor winding obtains the current I shown in the example functional block diagram AUXA timing diagram of the operation of an embodiment of the present invention. In operation, the current in the winding can be increased when the motor is stationary without generating continuous motor motion, and the switching circuit is configured to deliver the current. The current in the winding can be increased to above a threshold value that generates motor motion when the motor is in motion, and the switching circuit is configured to deliver the current.

[0049] Figure 3 is a timing diagram illustrating the operation of an embodiment for obtaining current from a motor winding. Figure 3 The LLS diagram shows Figure 2 Functional block diagram of the LLS switch 32 1 The ULS diagram shows Figure 2 Functional block diagram of the ULS switch 28 1 The high state indicates that the switch is closed, while the low state indicates that the switch is open. W The current in the windings of the motor 14 is shown. The positive current I W Indicates from winding terminal 14 AUX To node 38 1 The current in the positive direction, and the negative current I W Indicates that current flows from node 381 to winding terminal 14 AUX The current of the AUX , the current at the input of the auxiliary power supply 16 is shown. For the purpose of the following figure description, when the positive current I W exists and increases in the motor winding, assuming that it is coupled to the first end 14 of the motor winding VDD Half-bridge motor driver circuit 12 2 The HS switch is closed, and Figure 1 is shown coupled to the second end 14 of the motor winding AUX Half-bridge motor driver circuit 12 1 HS switch 24 1 is disconnected to allow current in the motor windings.

[0050] exist Figure 3 In the duration T STATIONARY During the period when the motor 14 is stationary, the current I AUX is delivered to the input of the auxiliary power supply 16 .

[0051] When at time T MOTION During the period when the motor is in motion, the ULS switch 28 1 and LLS switch 32 1 In t 0 is closed, and the current I W begins to increase in the winding. At t 1At, ULS switch 28 1 and LLS switch 32 1 is disconnected to allow the current I W Through diode 26 1 Return to the VDD power supply rail. 2 At, the current I W reaches its minimum value and there is negligible current in the winding.

[0052] When at time T STATIONARY During the period when the motor is stationary, the ULS switch 28 1 and LLS switch 32 1 In t 3 is closed, and the current I W Start to increase. 4 When the current I W When the threshold is reached, the LLS switches 32 1 is disconnected to allow the current I W is delivered to the auxiliary power supply 16, and the current I AUX Equal to the current I W In another embodiment, only the current I W part is delivered, and the current I AUX isI W part of t 5 At, ULS switch 28 1 is disconnected to allow the current I W For example, through the diode 26 1 returns to the VDD rail, and the current I AUX reaches its minimum value, which in one embodiment may be substantially zero or negligible current. 6 At time t, there is negligible current in the winding. 7 ,t 8 and t 9 Repeated to provide current I to the input of auxiliary power supply 16 AUX In the above description and the following description, it should be understood that in an actual motor control system, at time T STATIONARY During this period, the current I AUX To provide auxiliary power, a small torque can be initially introduced to the rotor of the motor in the system. STATIONARY During the period, the auxiliary power is supplied to the I AUX During the first few pulses of current, an initial small angular motion can be introduced into the motor rotor. However, this motion is temporary because during T STATIONARY During this period, the motor winding current is not as high as during T MOTIONThe sequence of generating continuous motion is excited as in the case of period T. STATIONARY The motor should be referred to as being at rest rather than at T MOTION Continuous rotation of the situation during.

[0053] Figure 4 is a timing diagram illustrating the operation of an additional embodiment for obtaining current from the motor windings. Figure 4 When at time T MOTION During the period when the motor 14 is in motion, the current I AUX is delivered to the input of the auxiliary power supply 16 .

[0054] In t 0 At, ULS switch 28 1 and LLS switch 32 1 is closed. Current I W Start to increase. 1 At, LLS switch 32 1 is disconnected to allow the current I AUX Enter the auxiliary power supply 16. At t 2 At, ULS switch 28 1 is disconnected and the current I W Reduce. 3 At time t, there is negligible current in the winding. 4 Repeat at.

[0055] Figure 5 is a timing diagram illustrating the operation of an additional embodiment for obtaining current from the motor windings. Figure 5 When at time T MOTION During the period when the motor 14 is in motion, the current I AUX is delivered to the input of the auxiliary power supply 16. In this embodiment, the current I W is delivered once to the auxiliary power supply 16 and then returned to the VDD power rail.

[0056] In t 0 At, ULS switch 28 1 and LLS switch 32 1 is closed. Current I W Start to increase. 1 At, LLS switch 32 1 is disconnected to allow the current I AUX Enter auxiliary power supply 16.

[0057] In t 2 At, LLS switch 32 1 is closed and the current I AUX becomes zero. At t 3 At, ULS switch 281 and LLS switch 32 1 is disconnected to allow the current I W Through diode 26 1 returns to the VDD supply rail. 4 At this point, there is a negligible current in the winding.

[0058] Figure 6 is a timing diagram illustrating the operation of an additional embodiment for obtaining current from the motor windings. Figure 6 When at time T MOTION During the period when the motor 14 is in motion, the current I AUX is delivered to the input of the auxiliary power supply 16 .

[0059] In t 0 At, ULS switch 28 1 and LLS switch 32 1 is closed. Current I W Start to increase. 1 At, ULS switch 28 1 and LLS switch 32 1 is disconnected to allow the current I W For example, through the diode 26 1 returns to the VDD supply rail. 2 At this point, there is a negligible current in the winding.

[0060] In t 3 At, ULS switch 28 1 is closed, the current in the winding increases, and the current I AUX is delivered to the input of the auxiliary power supply 16. At t 4 At, ULS switch 28 1 is disconnected to allow the current I W For example, through the diode 26 1 returns to the VDD supply rail. 5 At this point, there is a negligible current in the winding.

[0061] Figure 7 is a timing diagram illustrating the operation of an additional embodiment for obtaining current from the motor windings. Figure 7 When at time T MOTION During the time that the motor 14 is in motion, electrical current is delivered to the input of the auxiliary power source 16 .

[0062] In t 0 At, ULS switch 28 1 and LLS switch 32 1 is closed. Current I W Starts to increase from a non-zero value. 1At, LLS switch 32 1 is disconnected to allow the current I AUX Enter the input of the auxiliary power supply 16. At t 2 At, ULS switch 28 1 is disconnected to stop current flow into the auxiliary power input, thereby allowing the current I W For example, through the diode 26 1 returns to the VDD supply rail. 3 At , the current in the winding increases again from a non-zero value.

[0063] Figure 8 is a timing diagram illustrating the operation of an additional embodiment for obtaining current from the motor windings. Figure 8 When at time T MOTION During the time when the motor is in motion and when at time T STATIONARY Current is delivered at multiple intervals during which the motor is stationary.

[0064] When in T MOTION During the period when the motor is in motion, at t 0 At, ULS switch 28 1 and LLS switch 32 1 is closed. Current I W Start to increase. 1 At, ULS switch 28 1 and LLS switch 32 1 is disconnected to allow the current I W For example, through the diode 26 1 returns to the VDD rail. There is no switching of the input delivering current to the auxiliary supply. At t 2 At this point, there is a negligible current in the winding.

[0065] When at time T STATIONARY During this period, when the motor is stationary, at t 3 At, ULS switch 28 1 and LLS switch 32 1 is closed. Current I W Start to increase. 4 At, LLS switch 32 1 is disconnected to allow the current I AUX Enter the input of the auxiliary power supply 16. At t 5 At, LLS switch 28 1 is disconnected to allow the current I W For example, through the diode 26 1 returns to the VDD supply rail. 6 At time t, there is negligible current in the winding. 7 ,t8 ,t 9 and t 10 Repeated to provide current to the input of the auxiliary power supply.

[0066] When at time T MOTION During the period when the motor is in motion, at t 11 At, ULS switch 28 1 and LLS switch 32 1 is closed. Current I W Start to increase. 12 At, LLS switch 32 1 is disconnected to allow the current I AUX Enter the input of the auxiliary power supply 16. At t 13 At, LLS switch 28 1 is closed. 14 At, ULS switch 28 1 and LLS switch 32 1 can be disconnected to allow the current I W For example, through the diode 26 1 returns to the VDD supply rail. 15 At this point, there is a negligible current in the winding.

[0067] Fig. 9 is used for Figure 1 The half-bridge motor driver 12 shown in 1 A circuit diagram of an embodiment of the ULS switch 28 1 is a normally-on transistor having a 14 AUX The motor winding receives current I W The switch input and is coupled to the AUX node 36 1 Switch output. LLS switch 32 1 is a normally-off transistor having a gate coupled to the AUX node 36. 1 The input and the output are coupled to the reference ground. LS drive circuit 22 1 Receives a control signal from the system MCU 18 (not shown) and in response is configured to send a switch signal to the normally-on transistor 28 1 and normally-off transistor 32 1 The switch signal indicates when to increase the current in the winding and when to switch the current via the AUX node 36. 1 The current is delivered to the auxiliary power supply 16. It should be understood that the diode 30 1 and 34 1 The switches 28 may be 1 and 32 1The internal structure of either or both is inherent to the diode, not the discrete diode.

[0068] Fig.10 is used for Figure 1 The half-bridge motor driver 12 shown in 1 The ULS switch is a transistor such as a gallium nitride (GaN) transistor or a silicon JFET 40 1 A normally-on transistor having a second end 14 configured to receive a current from the motor winding AUX Receive current I W The drain of the 1 The LLS switch is a normally-off metal oxide semiconductor field effect transistor (MOSFET) 42 1 , which has a coupled to AUX node 36 1 The drain and the source are coupled to the reference ground. LS drive circuit 22 1 Receives a signal from the system MCU 18 (not shown) and in response is configured to send a switching signal to the MOSFET 42 1 The gate resistor 46 1 Coupling from ground to GaN transistor 40 1 In one embodiment, the Zener diode 44 1 Parallel coupled to MOSFET 42 1 To provide a clamp to limit the 1 The switch signal indicates when to increase the current in the winding and when to switch the current through the AUX node 36. 1 The current is delivered to the auxiliary power supply 16 .

[0069] Fig.11 Another embodiment of how the windings of the motor 14 may be configured to provide current to the auxiliary power supply 16 is illustrated. In one embodiment, the ULS switch is a normally-on gallium nitride (GaN) transistor 40 1 , which has a second end 14 configured to be connected from the motor winding AUX Receive current I W The drain of the 1 The LLS switch is a normally-off MOSFET 42 1 , which has a coupled to AUX node 36 1 The drain and the source are coupled to ground. LS drive circuit 22 1 Receives a signal from the system MCU 18 (not shown) and is configured to send a switching signal to the MOSFET 42 1 The gate resistor 46 1The switching signal indicates when to increase the current in the winding and when to deliver the current to the auxiliary power supply 16 via the auxiliary node.

[0070] An auxiliary switch 48, which may be part of the auxiliary power supply 16, is coupled to the AUX node 36. The auxiliary switch 48 may be a GaN transistor. LS drive circuit 22 1 It may also be configured to send an ENABLE signal to the auxiliary switch, which is used to indicate when the stored energy is to be delivered to the auxiliary power source 16 via the AUX node.

[0071] Fig.12 Another embodiment of a winding of the motor 14 configured to provide current to the auxiliary power supply 16 is illustrated. In one embodiment, the ULS switch is a normally-on GaN transistor 40 1 , which has a second end 14 configured to be connected from the motor winding AUX Receive current I W The drain of the 1 The LLS switch is a normally-off MOSFET 42 1 , which has a coupled to AUX node 36 1 The drain and the source are coupled to ground. LS drive circuit 22 1 Receives a signal from the system MCU 18 (not shown) and in response is configured to send a switching signal to the MOSFET 42 1 The gate resistor 46 1 Coupling from ground to GaN transistor 40 1 The switching signal indicates when current is established in the windings of the motor 14 and when current is delivered to the auxiliary power supply 16 via the auxiliary node.

[0072] The diode 52 and the external auxiliary switch 50 are coupled to the AUX node 36. 1 and the auxiliary power supply 16. The capacitor 54 is coupled to the cathode of the diode 52 and to ground. LS drive circuit 22 1 The AUX node 36 is also configured to send an enable signal to the external auxiliary switch 50, the enable signal being used to indicate when the auxiliary switch 50 is switched on via the AUX node 36. 1 The stored energy is delivered to the auxiliary power source 16 .

[0073] In this embodiment, the current I AUX The capacitor may be charged to a voltage limited by the Zener diode 44 , and the transistor 50 may switch current to the auxiliary power supply 16 .

[0074] Fig.13 is an example for Fig.12The timing diagram of the operation of the embodiment of the winding current acquisition shown in FIG. In this embodiment, the auxiliary switch determines the time at which the auxiliary switch is switched on at T S1 or T S2 When current is delivered to the AUX power supply 16 during when the motor is stationary or in motion.

[0075] The FET diagram shows a FET switch 42 1 The GaN diagram shows a GaN switch 40 1 The diagram AUX shows the state of the AUX switch 50. A high state indicates that the switch is closed, while a low state indicates that the switch is open. W The current in the windings of the motor 14 is shown. A positive current IW indicates a current flowing from the windings of the motor 14 to the node 38 1 The negative current I W Instructs from node 38 1 The current flowing to the windings of the motor 14. AUX The current at the input of the auxiliary power supply 16 is shown.

[0076] Duration T S1 The auxiliary switch 50 and the normally-on GaN transistor 40 are illustrated. 1 When is controlled synchronously. 0 At, the normally-on GaN transistor 40 1 , Normally Off FET 42 1 and the auxiliary switch 50 is closed. The current I W Start to increase. 1 When the current I W When the threshold is reached, the normally-off FET 42 1 is disconnected. The current is delivered to the auxiliary power supply. At t 2 At, the normally-on GaN transistor 40 1 and the auxiliary switch 50 is disconnected. At t 3 At this point, there is a negligible current in the winding.

[0077] Duration T S2 exemplifies when the auxiliary switch 50 and the normally-on GaN transistor 401 are asynchronously controlled. 4 At, the normally-on GaN transistor 40 1 and normally-off FET 42 1 is closed. Current I W Start to increase. 5 At t 6 At, normally-off FET 42 1 is disconnected. The current is delivered to the auxiliary power supply. At t 7 At, the normally-on GaN transistor 401 and the auxiliary switch 50 is disconnected. At t 8 At this point, there is a negligible current in the winding.

[0078] Fig.14A , Fig. 14B and Fig. 14C Illustrated Figure 1 Additional embodiments of the systems shown in . For each figure, a half-bridge motor driver circuit is coupled between a VDD power rail (not shown) and a reference ground. In a typical system, a single auxiliary power supply can provide power to all motor driver circuits in the system.

[0079] exist Fig.14A In the embodiment, the motor is a three-phase motor having three windings. For each winding, a first half-bridge motor driver circuit is coupled to the first terminal 14 VDD , and the second half-bridge motor driver circuit is coupled to the second terminal 14 AUX .

[0080] exist Fig. 14B In the embodiment, the motor has three windings arranged in a triangle configuration. For each pair of windings, a first half-bridge motor driver circuit is coupled to the first ends 14 of the two windings. VDD , and the second half-bridge motor driver circuit is coupled to the second ends of the two windings 14 AUX .

[0081] exist Fig. 14C In the embodiment, the motor has three windings in a Y-shaped configuration. For each winding, a first half-bridge motor driver circuit is coupled to a first end 14 of a winding. VDD , and the second half-bridge motor driver circuit is coupled to the second end 14 of the different winding AUX .

[0082] Fig.15 is a functional block diagram of another embodiment according to the present disclosure. 1 , 80 2 , 80 3 is coupled between VDD and reference ground.

[0083] As an exemplary embodiment, circuit block 80 1 A first switch Q10 is included, the first switch Q10 having an input terminal coupled to VDD and having a diode D1 coupled to the L The cathode of diode D1 is the output terminal. L The anode of the motor winding L1 is coupled to the reference ground. The motor winding L1 has a first terminal 14 coupled to the output of the first switch Q10. VDD and coupled to the composite switch S W1 The second input terminal 14AUX The composite switch S W1 The output is coupled to the reference ground. Diode D1 H The second end 14 of the motor winding L1 is coupled to VDD. AUX between.

[0084] Composite switch S W1 The invention comprises two transistors in a cascode configuration, for example, a normally-on transistor Q11 and a normally-off transistor Q12 coupled at an AUX node. The normally-on transistor Q11 may be a GaN transistor, and the normally-off transistor Q12 may be a MOSFET. The Zener diode D Z The resistor R1 is coupled in parallel to the normally-off transistor Q12. The resistor R1 is coupled between the gate of the normally-on transistor Q11 and the reference ground.

[0085] Diode D AUX The LS driver circuit is coupled between the AUX node and the drain of the auxiliary switch Q13. The source of the auxiliary switch Q13 is also coupled to the auxiliary power supply. The LS driver circuit is coupled to the gate of the normally-off transistor Q12 and to the gate of the auxiliary switch Q13.

[0086] To increase the current in the selected winding, switches Q10, Q11 and Q12 are closed.

[0087] To deliver current to the auxiliary power supply, the composite switch Q12 can be turned off to deliver current from the AUX node to the auxiliary switch Q13 until the voltage at the AUX node rises high enough to turn off the composite switch switch Q11. It should be understood that in another embodiment (not shown), the capacitor can be connected from D AUX and the node of the auxiliary switch Q13 is coupled to the reference ground, as Fig.12 The capacitor 54 is shown in FIG.

[0088] Fig.16 1 is a process flow diagram 100 according to an embodiment of the present disclosure. In step 102, it is determined whether the auxiliary power supply requires current. If not, step 102 is repeated. If yes, in step 104, current is established in the winding. This can be achieved by applying one of the example switch diagrams previously disclosed.

[0089] In step 106 , current from the winding is delivered to an auxiliary power supply.

[0090] The above description of the illustrated embodiments of the utility model, including the content described in the abstract, is not intended to be exhaustive or to limit the exact form disclosed. Although specific embodiments and embodiments of the utility model are described herein for illustrative purposes, various equivalent modifications are possible without departing from the broader spirit and scope of the utility model. In fact, it should be understood that specific example voltages, currents, frequencies, power range values, times, etc. are provided for the purpose of explanation, and other values ​​may also be adopted in other embodiments and embodiments according to the teachings of the utility model.

[0091] These modifications can be made to the embodiments of the utility model in view of the above specific embodiments. The terms used in the appended claims should not be understood to limit the utility model to the specific embodiments disclosed in the specification and claims. Instead, the scope will be determined entirely by the appended claims, which will be interpreted according to established claim interpretation theories. This specification and the drawings are therefore considered to be illustrative rather than restrictive.

[0092] As an example, a switch mode power converter can have an inductive energy storage element as a winding of a motor. As previously described, in a first state, energy can be stored as current in the winding of the motor, and in a second state, a portion of the current in the winding can be delivered to an auxiliary node. The dc-dc converter can be modified accordingly. Suitable dc-dc converters can include variations of members in the series of flyback converters, buck converters, and boost converters. The first state and the second state will be based on operating parameters of the load, duty cycle, time, current in the winding, and power requirements of the auxiliary power supply. For illustration, the power requirement can be a comparison of a desired output quantity (e.g., voltage) with a reference voltage.

Claims

1. A motor drive for coupling to an auxiliary power source and to a winding of a motor, the motor drive comprising: a control circuit coupled to the switch circuit to switch the switch circuit to receive current and to switch the switch circuit to deliver current, Characterized in that the motor driver also includes the switching circuit, which has an auxiliary node coupled to the auxiliary power supply and a winding node coupled to the winding, and the switching circuit is coupled to receive current and store energy in the inductance of the winding and deliver current to the auxiliary power supply.

2. The motor driver according to claim 1, characterized in that: The switch circuit comprises: an upper switch coupled to the winding node and to the auxiliary node; and A lower switch is coupled to the auxiliary node and to a reference ground.

3. The motor driver according to claim 2, characterized in that: The upper switch and the lower switch include a cascode configuration of a normally-on transistor and a normally-off transistor.

4. The motor driver according to claim 3, characterized in that: The normally-on transistor is selected from the group consisting of a GaN transistor and a SiC transistor.

5. The motor driver according to claim 3, characterized in that: The normally-off transistor is a MOSFET.

6. The motor driver according to claim 3, characterized in that: The switch circuit is an integrated circuit.

7. A system comprising: a switch of a first motor driver, the switch coupled to a supply rail; a motor having a winding coupled to the switch; a second motor driver having a winding node coupled to the winding to receive current from the supply rail, Features: The second motor driver has an auxiliary node to deliver current; and The system includes an auxiliary power supply coupled to an auxiliary node of the second motor drive.

8. The system according to claim 7, characterized in that The second motor driver comprises: a control circuit coupled to send a control signal indicating when to deliver the current; and a switch circuit coupled to the winding node, the switch circuit having an auxiliary node coupled to the auxiliary power supply, the switch circuit further coupled to receive the control signal and generate an enable signal, the switch circuit comprising: an upper switch coupled to the winding node and to the auxiliary node, and A lower switch is coupled to the auxiliary node and to a reference ground.

9. The system according to claim 8, characterized in that The system also includes an auxiliary switch coupled to the auxiliary node and to the auxiliary power supply, wherein the auxiliary switch is coupled to receive the enable signal from the switch circuit.

10. The system according to claim 8, characterized in that The switching circuit is coupled to deliver current based on an operating parameter of the auxiliary power supply, wherein the operating parameter is selected from the group consisting of duty cycle, time, current in the winding, and power demand of the auxiliary power supply.

11. A switch mode power converter comprising: an inductive energy transfer element having a first end and a second end, Features: The inductive energy transfer element includes windings of a motor; The switch-mode power converter further includes a switch circuit having an auxiliary node, the switch circuit coupled to the first end of the winding and to a reference ground; and A drive circuit includes the switch circuit and is configured to receive a control signal indicating when to store energy in the inductance of the winding and when to deliver energy to the auxiliary node.

12. The switch mode power converter according to claim 11, characterized in that The switch mode power converter is a dc-dc converter.

13. The switch mode power converter according to claim 12, wherein: The switch-mode power converter is coupled to receive current and to deliver current based on an operating parameter of an auxiliary power source coupled to the auxiliary node, and The operating parameter is selected from the group consisting of duty cycle, time, current in the winding, and power demand of the auxiliary power supply.

14. A system comprising: a half-bridge, the half-bridge comprising a high-side switch, a high-side driver circuit coupled to the high-side switch of the half-bridge; a system controller coupled to provide control signals to the high-side driver circuit and the low-side driver circuit; Features: The half-bridge further includes a composite low-side switch coupled in series with the high-side switch to define a winding node therebetween, wherein the composite low-side switch includes an upper low-side switch and a lower low-side switch coupled in series to define an auxiliary node therebetween; and The system also includes the low-side driver circuit coupled to the composite low-side switch of the half-bridge, and An auxiliary power supply is coupled to provide power to the system controller, wherein the auxiliary power supply is further coupled to receive power from the auxiliary node defined between the upper low-side switch and the lower low-side switch.

15. The system according to claim 14, characterized in that: The upper low-side switch is a normally-on transistor; The lower low-side switch is a normally-off transistor; and The low-side drive circuit is coupled to drive the composite low-side switch in a cascode configuration.

16. The system according to claim 15, characterized in that The lower low-side switch is a GaN transistor.

17. The system according to claim 14, characterized in that The system also includes an external auxiliary switch coupled between the auxiliary node and the auxiliary power supply.

18. The system according to claim 17, characterized in that The system controller is coupled to provide an enable signal to the external auxiliary switch.

19. The system according to claim 17, characterized in that The system further comprises: a diode having an anode coupled to the auxiliary node and a cathode coupled to the external auxiliary switch; and A capacitor is coupled between the cathode of the diode and ground.

20. The system according to claim 14, characterized in that The system also includes a motor having a motor winding coupled to the winding node.

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