1、DRV8801EVMTPS77701 LDO MSP430TM MCU DRV8801Single H-Bridge Motor Driver MBattery+5 V from USB +8 V to +38 V(+6.5 V to +38 V for DRV8801A-Q1 version)Copyright 2016, Texas Instruments Incorporated1TIDU301AApril 2014Revised November 2016Submit Documentation FeedbackCopyright 20142016, Texas Instruments
2、 IncorporatedAutomotive Brushed Motor Drive for Power-Folding Side Mirrors ReferenceDesignTI DesignsAutomotive Brushed Motor Drive for Power-Folding SideMirrors Reference DesignDescriptionThis TI Design features the DRV8801EVM and theDRV8872EVM. These evaluation modules (EVMs)enable an easy-to-use p
3、latform to demonstrate thecapability and performance of the DRV8801 andDRV8872 motor drivers for power-folding side mirrors.This TI Design also intends to allow easy evaluation ofthe automotive qualified versions of the DRV8801 andDRV8872 (DRV8801-Q1 and DRV8872-Q1). TheDRV8801-Q1 is a 2.8-A peak, f
4、ull-bridge, brushed DCmotor driver capable of driving the retracting functionof vehicle side view mirrors. With the built-inautomotive protection features of overcurrent, thermal,shoot-through, UVLO, and wide-input voltage (wideVIN) range, this motor driver provides the necessaryfeatures to survive
5、a harsh automotive environment.Additionally, this TI Design provides test data to allowthe designer to quickly evaluate the performance ofthe DRV8801-Q1 and the DRV8872-Q1 for theirfolding-mirror modules.ResourcesTIDA-00145 Design FolderDRV8801 Product FolderDRV8801-Q1 Product FolderDRV8872 Product
6、FolderDRV8872-Q1 Product FolderTPS77701 Product FolderMSP430F1612 Product FolderASK Our E2E ExpertsFeatures Single H-Bridge Motor Driver With IntegratedProtection Features of Overcurrent, Thermal, andUndervoltage Lockout for Higher System ReliabilityOvervoltage Protection: 45 V Wide 8-V to 36-V Inpu
7、t Supply Range EasilySupports +12-V and +24-V Industry StandardSupplies High 2.8-A Peak Current Helps Support LargeStartup and Stall Inrush Currents EVM includes easy to use GUI Phase and Enable Control Interface ProvidesSimple, 2-pin Control Interface for Motor Operation Brake Mode Support Allows t
8、he Motor to StopQuickly Available AEC-Q100 Device Options for EVM ICsApplications Automotive Body and Convenience Electronics Car Side-View Mirrors Grill ShuttersTPS7A1601VM to 3.3-V LDOMSP430TM MCU(Shown but not used)DRV8872Single H-Bridge Motor DriverStall Detection CircuitMBatteryCopyright 2016,
9、Texas Instruments IncorporatedDRV8801EVMTPS77701 LDO MSP430TM MCU DRV8801Single H-Bridge Motor Driver MBattery+5 V from USB +8 V to +38 V(+6.5 V to +38 V for DRV8801A-Q1 version)Copyright 2016, Texas Instruments IncorporatedSystem Overview 2 TIDU301AApril 2014Revised November 2016Submit Documentatio
10、n FeedbackCopyright 20142016, Texas Instruments IncorporatedAutomotive Brushed Motor Drive for Power-Folding Side Mirrors ReferenceDesignAn IMPORTANT NOTICE at the end of this TI reference design addresses authorized use, intellectual property matters and otherimportant disclaimers and information.1
11、 System Overview1.1 Block DiagramFigure 1 shows the DRV8801 block diagram, and Figure 2 shows the DRV8872 block diagram.Figure 1. DRV8801 Block DiagramFigure 2. DRV8872 Block D System Overview3TIDU301AApril 2014Revised November 2016Submit Documentation FeedbackCopyright 20142016, Texas Instruments I
12、ncorporatedAutomotive Brushed Motor Drive for Power-Folding Side Mirrors ReferenceDesign1.2 Design ConsiderationsLinear Regulator: The EVM uses the TPS77071 LDO to power the MCU, but the designer may alsoconsider the TPS7A66xx and TPS7A69xx LDOs from TIs automotive high-voltage LDO portfolio. LDOs i
13、nthe TPS7A66xx and TPS7A69xx part families feature a low 12-A quiescent current and short-circuit andovercurrent protection.MCU: The motor operation through the motor driver interface of the 2-pin control is managed by theonboard MSP430. TI has automotive qualified MSP320 devices, and TI recommends
14、theMSP320F2272-Q1 for this design.Motor: Because most motor-driven automotive convenience features do not require highly efficient motorsand cost is typically more of a concern, a brushed motor was selected for the wing-mirror folding function.Motor Driver, DRV8801: The DRV8801 is a single H-bridge,
15、 integrated motor driver with protectionfeatures and can handle the necessary current to fold a mirror. Also, while the DRV8801 onboard the EVMis not automotive qualified, TI has an automotive qualified version (DRV8801-Q1) available. Theautomotive version supports the same features and functionalit
16、y.Motor Driver, DRV8872: The DRV8872 is a single H-bridge, integrated motor driver with protectionfeatures and can handle the necessary current to fold a mirror. Also, while the DRV8872 onboard the EVMis not automotive qualified, TI has an automotive qualified version (DRV8872-Q1) available. Theauto
17、motive version supports the same features and functionality.Getting Started Hardware and Software 4 TIDU301AApril 2014Revised November 2016Submit Documentation FeedbackCopyright 20142016, Texas Instruments IncorporatedAutomotive Brushed Motor Drive for Power-Folding Side Mirrors ReferenceDesign2 Get
18、ting Started Hardware and Software2.1 HardwareThe following list details the equipment used for testing. Oscilloscope Current probe 3 power supplies 1 12-V power supply 2 3.3-V power supplies DRV8801EVM (or DRV8872EVM) Power-folding side mirror (TYC1200142)Figure 3 shows the power-folding mirror wit
19、h the DRV8801EVM.Figure 3. Power-Folding Mirror With DRV8801EVM2.2 SoftwareUsers must have the DRV8801EVM GUI installed on a PC to perform tests.To PC + GUICtrl signal (3.3 V or 0 V)Ctrl signal (3.3 V or 0 V)scopeGNDscope+ current probeTomotorscopeGND12V Testing and Results5TIDU301AApril 2014Revise
20、d November 2016Submit Documentation FeedbackCopyright 20142016, Texas Instruments IncorporatedAutomotive Brushed Motor Drive for Power-Folding Side Mirrors ReferenceDesign3 Testing and Results3.1 DRV8801EVM3.1.1 Test SetupFigure 4 shows the board with labeled connections.Figure 4. DRV8801EVM Board C
21、onnectionsUse the following instructions for test setup.1. Install the EVM graphics user interface (GUI), then connect the PC to the DRV8801EVM using USBCONN (J4).2. Connect the 12-V power supply and ground to the DRV8801EVM through +VM and VM, respectively(J2).3. Connect the motor leads to the DRV8
22、801EVM through Motor Out (J3).4. Connect the TS_PHASE and TS_ENABLE pins to the 3.3-V power supplies.The firmware and GUI (as is) only support pulse width modulation (PWM) control, so connecting thepins to a logic supply can simplify the testing to provide 100% duty cycle signals.5. Connect the scop
23、e leads to the DRV8801EVM at TS_OUT+ and TS_OUT.6. Connect the scope and current probe to the DRV8801 through TS_SENSE.3.1.2 Motor CharacterizationTo measure resistance and inductance, the motor leads were probe with a multimeter. Motor resistance: 63.4 Motor inductance: 127 mHThe expected current d
24、raw at an input off 12 V is approximately 200 mA (12 V / 63.4 = 189 mA).Testing and Results 6 TIDU301AApril 2014Revised November 2016Submit Documentation FeedbackCopyright 20142016, Texas Instruments IncorporatedAutomotive Brushed Motor Drive for Power-Folding Side Mirrors ReferenceDesign3.1.3 Start
25、-UpFigure 5 shows the motor moving forward from a stopped position. Though the peak current isapproximately 5 A, overcurrent is not tripped because the peak lasts for less time than the overcurrentdeglitch time of 3 s (see red arrow).See the electrical characteristics table of DRV8801-Q1 DMOS Full-B
26、ridge Motor Drivers for overcurrentspecifications. This motor has a large starting torque (required to overcome inertia) and consequentlyrequires a high amount of current to initially move the motor.Figure 5. Motor Folding Forward From Stopped PositionFigure 6 shows the motor moving in reverse from
27、a stopped position. Though the peak current isapproximately 5 A, overcurrent is not tripped because the peak lasts for less time than the overcurrentdeglitch time of 3 s (see red arrow).See the electrical characteristics table of DRV8801-Q1 DMOS Full-Bridge Motor Drivers for overcurrentspecification
28、s. Notice that OUT+, OUT, and CUR are inverted from Figure 5.Figure 6. Motor Folding in Reverse From Stopped P Testing and Results7TIDU301AApril 2014Revised November 2016Submit Documentation FeedbackCopyright 20142016, Texas Instruments IncorporatedAutomotive Brushed Motor Drive for Power-Folding Si
29、de Mirrors ReferenceDesign3.1.4 Steady StateFigure 7 shows the motor moving forward in steady state. Starting torque requirements have been met.The current is low in this region of operation. In Figure 7, the forward steady state DC current (with enableat 100% duty cycle), is 375 mA.Figure 7. Motor
30、Folding Forward in Steady StateIn Figure 8, the reverse steady state DC current (with enable at 100% duty cycle) is 211 mA.Figure 8. Motor Folding Reverse in Steady StateTesting and Results 8 TIDU301AApril 2014Revised November 2016Submit Documentation FeedbackCopyright 20142016, Texas Instruments In
31、corporatedAutomotive Brushed Motor Drive for Power-Folding Side Mirrors ReferenceDesign3.1.5 Track Resistance (Near end of Track)Before the motor stall, the motor encounter mechanical resistance along the track. This resistance isdependant upon the housing and mechanical surroundings of the motor. I
32、n Figure 9, the pink curvedpulses (CUR) represent the track resistance.Figure 9. Track Resistance (Pink) for Forward DirectionFigure 10 shows the track resistance in reverse. Based on the steepness of the pink signal (CUR), themotor hits more resistance quicker than when moving forward.Figure 10. Tr
33、ack Resistance (Pink) for Reverse D Testing and Results9TIDU301AApril 2014Revised November 2016Submit Documentation FeedbackCopyright 20142016, Texas Instruments IncorporatedAutomotive Brushed Motor Drive for Power-Folding Side Mirrors ReferenceDesign3.1.6 StallWhen the motor reaches the end of the
34、track, the motor continues to move forward and eventually stallswhen a fault or overcurrent detection is tripped (depending on the motor driver). After the motor stalls, thecurrent drops. Figure 11 through Figure 13 shows the motor stall behavior.Figure 11. Forward Direction Motor StallingFigure 12.
35、 Zoomed-in Image of Figure 11Figure 13. Reverse Direction Motor StallingTesting and Results 10 TIDU301AApril 2014Revised November 2016Submit Documentation FeedbackCopyright 20142016, Texas Instruments IncorporatedAutomotive Brushed Motor Drive for Power-Folding Side Mirrors ReferenceDesign3.1.7 Ther
36、mal ImagingFigure 14 shows the thermal image of the board taken with an FLIR thermal camera. The power foldingside mirror was repeatedly opened and closed for 10 minutes before the thermal image was taken.Additionally, Figure 14 shows most of the heat (red) dissipated through the DRV8801 and thecorr
37、esponding sense resistor.Figure 14. DRV8801EVM After 10 Minutes of Continual Operation10.0kR110.0kR23.01kR37.15kR447pFC1GNDDRV8872_OUT1DRV8872_OUT2nSTALLSta ll d ete ction circuitDurin g normal operation, th e moto r will run with one output hig h and th e oth erlo w. This will c reate a lo gic hig
38、h as an in put to the m cu.At startup and stall, the current regulation circuit will activate. This will create aperiodic logic low as an input to the m cu. This high to low transition can be usedas an interrupt to the m cu to signal a possible stall.At 10.8V, nSTALL toggles fro m 0 to 2.5VAt 14.4V
39、nSTALL toggles from 0 to 3.3VAdditional protection circuitry can include a zener diode from n STALL to ground(shown below)3.6VD1MMSZ5227B-7-FOp tion al 3.6 V ze ne r d io de to grou ndCopyright 2016, Texas Instruments I Testing and Results11TIDU301AApril 2014Revised November 2016Submit Documentation
40、 FeedbackCopyright 20142016, Texas Instruments IncorporatedAutomotive Brushed Motor Drive for Power-Folding Side Mirrors ReferenceDesign3.2 DRV8872EVM3.2.1 Test SetupFigure 15 shows the DRV8872EVM device.Figure 15. DRV8872EVMUse the following instructions for test setup.1. Create a stall detection c
41、ircuit (see Figure 16).2. Connect the 12-V power supply and ground to the DRV8872EVM through VM and GND, respectively.3. Connect the motor leads to the DRV8872EVM through OUT1 and OUT2.4. Connect the scope leads to the DRV8872EVM at OUT1, OUT2, and nSTALL.5. Connect the scope and current probe to th
42、e DRV8872 through OUT1.6. Control the forward or reverse direction by connecting IN1 or IN2 to V5P0.Figure 16. Stall Detection CircuitTesting and Results 12 TIDU301AApril 2014Revised November 2016Submit Documentation FeedbackCopyright 20142016, Texas Instruments IncorporatedAutomotive Brushed Motor
43、Drive for Power-Folding Side Mirrors ReferenceDesign3.2.2 Start-UpFigure 17 shows the motor moving forward from a stopped position. The peak current is limited by thecurrent sense resistor (a 0.3- resistor limits the current to 700 mA). During start up, the current is limitedand the output toggles b
44、etween drive forward and slow decay. The stall detection current can be ignoredduring this time.Figure 17. Motor Folding Forward From Stopped Position (Zoom-in is Start-up Position Showing CurrentRegulation)Figure 18 shows the motor moving in reverse from a stopped position. Like Figure 17, the curr
45、ent islimited by the current sense resistor.Figure 18. Motor Folding in Reverse From Stopped Position (Zoom-in is Start-up Position ShowingCurrent Regulation) Testing and Results13TIDU301AApril 2014Revised November 2016Submit Documentation FeedbackCopyright 20142016, Texas Instruments IncorporatedAu
46、tomotive Brushed Motor Drive for Power-Folding Side Mirrors ReferenceDesign3.2.3 Steady StateFigure 19 shows the motor moving forward in steady state. The starting torque requirements have beenmet. The current is low and current regulation is not required in this region of operation. In Figure 19, t
47、heforward steady state DC current (with enable at 100% duty cycle), 375 mA.Figure 19. Motor Folding Forward in Steady StateIn Figure 20, the reverse steady-state DC current (with enable at 100% duty cycle) is 211 mA.Figure 20. Motor Folding in Reverse in Steady StateTesting and Results 14 TIDU301AAp
48、ril 2014Revised November 2016Submit Documentation FeedbackCopyright 20142016, Texas Instruments IncorporatedAutomotive Brushed Motor Drive for Power-Folding Side Mirrors ReferenceDesign3.2.4 StallWhen the motor reaches the end of the track, the motor continues to move forward and eventually stalls.A
49、s the current increases above the 700-mA threshold, current regulation begins and can be used to detectthe stall. The stall detector circuit begins to toggle between logic 0 and logic 1. See Figure 21 andFigure 22.Figure 21. Forward-Direction Motor Stalling (Zoom-in is Stalled Position Showing Current Regulation)Figure
