M880/M840MicrosteppingDriverManualV1.0
Tel: +086 0755-264343697WebSite: www.leadshine.com
6. PowerSupply Selection
TheM880and theM840canmatchmediumand small size steppingmotors(fromNema size 17 to
43)madebyLeadshineorothermotormanufactures around theworld.Toachievegood driving
performances,it isimportanttoselectsupplyvoltageand outputcurrentproperly.Generallyspeaking,
supplyvoltagedetermines thehighspeedperformance ofthemotor,whileoutputcurrentdetermines
theoutputtorqueofthedrivenmotor(particularlyatlowerspeed).Highersupplyvoltagewill allow
highermotorspeedtobeachieved,attheprice ofmorenoiseand heating.Ifthemotion speed
requirementislow,it sbettertouse lowersupplyvoltagetodecrease noise,heatingandimprove
reliability.
Regulated orUnregulated PowerSupply
Bothregulatedandunregulatedpowersupplies canbeusedtosupplythedriver.However,
unregulatedpowersupplies arepreferredduetotheirabilitytowithstandcurrentsurge.Ifregulated
powersupplies (suchas mostswitchingsupplies.)areindeedused,it isimportanttohavelarge
currentoutputratingtoavoidproblemslikecurrentclamp,forexampleusing4Asupplyfor3A
motor-driveroperation. Ontheotherhand, ifunregulatedsupplyisused, onemayuse apowersupply
oflowercurrentratingthanthatofmotor(typically50%～70%ofmotorcurrent).Thereason isthat
thedriverdrawscurrentfromthepowersupplycapacitoroftheunregulatedsupplyonlyduringthe
ON durationofthePWMcycle,butnotduringtheOFF duration.Therefore,theaveragecurrent
withdrawnfrompowersupplyisconsiderablyless thanmotorcurrent.Forexample,two3Amotors
canbewell suppliedbyonepowersupplyof4Arating.
Multiple Drivers
It isrecommendedtohavemultipledriverstoshareonepowersupplytoreduce cost,ifthesupply
has enoughcapacity.Toavoidcross interference, DONOT daisy-chainthepowersupplyinputpins
ofthedrivers. (Instead,please connectthemtopowersupplyseparately.)
Attention: NEVERconnectpowerand groundinthewrongdirection,as itwill damagetheM880or
theM840.
Selecting SupplyVoltage
ThepowerMOSFETSinsidetheM880andtheM840 canactuallyoperatewithin+24V～+80VDC,
includingpowerinputfluctuationand backEMF voltagegeneratedbymotorcoilsduringmotorshaft
deceleration.Highersupplyvoltagecanincrease motortorqueathigherspeeds,thushelpfulfor
avoidinglosingsteps.However,highervoltagemaycause biggermotorvibrationatlowerspeed,and
it mayalsocause over-voltageprotectionorevendriverdamage.Therefore,it issuggestedtochoose
onlysufficientlyhighsupplyvoltageforintendedapplications,and it issuggestedtouse power
supplies withtheoreticaloutputvoltageof+24～+75V,leavingroomforpowerfluctuation and
M880/M840MicrosteppingDriverManualV1.0
Tel: +086 0755-264343698WebSite: www.leadshine.com
back-EMF.
7. Selecting MicrostepResolutionand DriverOutputCurrent
Thisdriveruses an8-bitDIPswitchtosetmicrostepresolution,andmotoroperatingcurrent,as
shownbelow:
Microstep Resolution Selection
Microstepresolution issetbySW5, 6, 7, 8oftheDIPswitch as showninthefollowingtable:
Microstep
Steps/rev.(for1.8°motor) SW5 SW6 SW7 SW8
2 400 ON ON ON ON
4 800 ON OFF ON ON
8 1600 ON ON OFF ON
16 3200 ON OFF OFF ON
32 6400 ON ON ON OFF
64 12800 ON OFF ON OFF
128 25600 ON ON OFF OFF
256 51200 ON OFF OFF OFF
5 1000 OFF ON ON ON
10 2000 OFF OFF ON ON
25 5000 OFF ON OFF ON
50 10000 OFF OFF OFF ON
125 25000 OFF ON ON OFF
250 50000 OFF OFF ON OFF
CurrentSettings
Foragivenmotor,higherdrivercurrentwill makethemotortooutputmoretorque,butatthesame
timecausesmoreheatinginthemotoranddriver.Therefore,outputcurrentisgenerallysettobesuch
thatthemotorwill notoverheatforlongtimeoperation.Since parallelandserialconnectionsof
motorcoilswill significantlychangeresultinginductance andresistance,itisthereforeimportantto
setdriveroutputcurrentdependingonmotorphase current,motorleadsandconnectionmethods.
Phase currentratingsuppliedbymotormanufacturerisimportantinselectingdrivercurrent, however
theselection alsodependson leadsand connections.
Thefirstthree bits(SW1,2,3)oftheDIPswitchareusedtosetthedynamiccurrent.Selectasetting
