SLA7024M, SLA7026M,
AND
SMA7029M
HIGH-CURRENT PWM,
UNIPOLAR STEPPER MOTOR
CONTROLLER/DRIVERS
TYPICAL STEPPER MOTOR APPLICATIONS
(Half of Device Shown)
SMA7029M
V BB
A
IN B
A
OUT
B
8
V
CC
14
10
15
OUT
B
REG.
V b +5 V
R 1 510
Ω
TO
CHANNEL
A
VREF
13
+
+
R 2 100
Ω
2.4 kΩ
R
5
td
11
12
SENSE
9
+5 V
R 3 47 kΩ
OPEN-COLLECTOR
INVERTER
C1
470 pF
C 3 2200 pF
R
S
≤1 Ω
Dwg. EK-008-1
TRUTH TABLES
(SMA7029M Only)
WAVE DRIVE (FULL STEP) for SMA7029M
Sequence
Input A
Input tdA*
Input B
Input tdB*
Output ON
0
H
L
L
L
A
1
L
L
H
L
B
2
L
H
L
L
A
3
L
L
L
H
B
0
H
L
L
L
A
2- PHASE (FULL STEP) OPERATION
for SMA7029M
Sequence
Input A
Input B
Outputs ON
0
H
L
AB
1
H
H
AB
2
L
H
AB
3
L
L
AB
0
H
L
AB
*Logic signals to external open-collector inverter connected to t
dA
and t
dB
.