Data Sheet

GND
nHOME
MODE2
MODE1
MODE0
NC
STEP
nENBL
DIR
DECAY
nFAULT
nSLEEP
nRESET
V3P3OUT
CP1
CP2
VCP
VMA
AOUT1
ISENA
AOUT2
BOUT2
ISENB
BOUT1
VMB
AVREF
BVREF
GND
DRV8825
PPAD
0.01 µF
0.1 µF
200 m
200 m
1 M
+
±
Stepper
Motor
+
±
0.1 µF
0.1 µF
100 µF
VM
+
0.47 µF
V3P3OUT
10 k
V3P3OUT
10 k
V3P3OUT
V3P3OUT
50 k
30 k
DRV8825
SLVSA73F –APRIL 2010–REVISED JULY 2014 www.ti.com
9 Application and Implementation
9.1 Application Information
The DRV8825 is used in bipolar stepper control. The microstepping motor driver provides additional precision
and a smooth rotation from the stepper motor. The following design is a common application of the DRV8825.
9.2 Typical Application
9.2.1 Design Requirements
Design Parameter Reference Example Value
Supply Voltage VM 24 V
Motor Winding Resistance RL 3.9 Ω
Motor Winding Inductance IL 2.9 mH
Motor Full Step Angle θstep 1.8°/step
Target Microstepping Level nm 8 µsteps per step
Target Motor Speed v 120 rpm
Target Full-Scale Current IFS 1.25 A
9.2.2 Detailed Design Procedure
9.2.2.1 Stepper Motor Speed
The first step in configuring the DRV8825 requires the desired motor speed and microstepping level. If the target
application requires a constant speed, then a square wave with frequency ƒ
step
must be applied to the STEP pin.
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