Data Sheet
VM
VCP
AOUT1
AOUT2
BOUT1
BOUT2
NFAULT
VINT
AISEN
BISEN
GND
NENBL/AENBL
STEP/BENBL
DIR/BPHASE
M0/APHASE
M1
CONFIG
VREFO
AVREF
BVREF
ADECAY
NSLEEP
BDECAY
VM
L=Enable H = Disable
STEP Pulse
Direction
Step Mode M0
LOW = SLEEP
VM
10 uf
0.01 uf
2.2 uf
51K 51K
Stepper
Step Mode M1
VINT
DRV8834
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SLVSB19D –FEBRUARY 2012–REVISED MARCH 2015
9.2.3 Indexer Mode Driving a Stepper Motor
In indexer mode, only a rising edge on the STEP pin is needed to move the motor to the next step. The DIR pin
sets which direction the motor rotates, by reversing the step sequence. The internal indexer can operate in full-
step, half-step, and smaller microsteps up to 1/32-step, depending on the state of the M0 and M1 pins. The M0
and M1 pins can also be connected directly to ground or to VINT to program the step modes, if desired. If the
sleep function is not needed, nSLEEP can be connected to VM with an approximate 47-kΩ resistor. Step
sequences for full and half step are shown below.
Figure 16. Indexer Mode Driving a Stepper Motor
9.2.3.1 Design Requirements
Table 7 lists the design parameters.
Table 7. Design Parameters
PARAMETER REFERENCE EXAMPLE VALUE
Supply Voltage V
M
6 V
Motor Winding Resistance R
L
3.9 Ω
Motor Winding Inductance I
L
2.9 mH
Motor Full Step Angle θ
step
1.8°/step
Target Microstepping Level n
m
8 µsteps per step
Target Motor Speed V 120 RPM
Target Full-Scale Current I
FS
1.25 A
9.2.3.2 Detailed Design Procedures
Phase/enable mode can be used with a simple interface to a controller to operate a stepper motor in full or half
step modes. The decay mode can be set by changing the values of the resistors connected to the ADECAY and
BDECAY pins. The M1 pin is driven to logic high (by connecting to the VINT supply), to allow a zero-current (off)
state when the xENBL pin is set low. Coil current is set by the R
SENSE
resistors. If the sleep function is not
needed, nSLEEP can be connected to VM with an approximate 47-kΩ resistor.
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