2-Phase Stepper Motor Bipolar Driver IC (4W1-2 Phase Excitation/Micro-step Support)
A3957SLB
sInternal
Block Diagram
V
BB
UVLO
AND
TSD
MOTOR
SUPPLY
C
BB
OUT
A
OUT
B
PHASE
CONTROL
LOGIC
AND
LEVEL
SHIFT
V
CC
DECAY MODE
CONTROL
PFD
−
+
BLANKING
TIME AND
DRIVER
T
OFF
CONTROL
(000X)
−
+
SENSE
R
S
REF
D3
D2
16
LEVEL
DAC
GND
RC
D0
D1
R
T
C
T
sTruth
Table
Power Outputs
D3, D2, D1, D0
0000 or 0001
1XXX
or
X1XX
or
XX1X
PHASE OUTA
X
Z
H
H
OUTB
Z
L
PFD
X
≥3.5V
1.2V to 2.9V
≤0.8V
≥3.5V
1.2V to 2.9V
≤0.8V
Power Output Operating Mode
Disable
Forward, slow current-decay mode
Forward, mixed current-decay mode
Forward, fast current-decay mode
Reverse, slow current-decay mode
Reverse, mixed current-decay mode
Reverse, fast current-decay mode
L
L
H
X: Don’t care
High impedance (source and sink both OFF)
DAC
D3
1
1
1
1
1
1
1
1
D2
1
1
1
1
0
0
0
0
D1
1
1
0
0
1
1
0
0
D0
1
0
1
0
1
0
1
0
DAC [%]
100
95.7
91.3
87.0
82.6
78.3
73.9
69.6
D3
0
0
0
0
0
0
0
0
D2
1
1
1
1
0
0
0
0
D1
1
1
0
0
1
1
0
0
D0
1
0
1
0
1
0
1
0
DAC [%]
60.9
52.2
43.5
34.8
26.1
17.4
0
0
sApplication
Circuit
VBB
Vcc
+
Phase1
D10
D11
D12
D13
REF1
PFD1
10
20
13
11
8
3
2
5
CT1
RT1
Rs
6,7,
18,19
17
15
9
23
C
BB
+
C
CC
23
9
10
20
15
13
11
8
3
6,7,
18,19
17
5
CT2
Rs
RT2
2
Phase2
D20
D21
D22
D23
REF2
PFD2
A3957SLB
22
22
A3957SLB
qOff-time
setting : t
OFF
≅R
T
•
C
T
R
T
=36Ω (12kΩ to 100kΩ)
C
T
=560pF (470pF to 1500pF)
R
S
=0.51Ω (0.39Ω to 0.62Ω)
C
BB
=100
µ
F+0.1
µ
F
C
CC
=0.1
µ
F
V
REF
=0.5V to 2.5V
V
PFD
=1.2V to 2.9V (Mixed current-decay mode)
≥3.5V
(Slow current-decay mode)
≤0.8V
(Fast current-decay mode)
96
A3957SLB