A3955
Full-Bridge PWM Microstepping Motor Driver
ELECTRICAL CHARACTERISTICS at T
A
= 25°C, V
BB
= 5 V to 50 V, V
CC
= 4.5 V to 5.5 V
(unless otherwise noted.)
Limits
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Units
Power Outputs
Load Supply Voltage Range
Output Leakage Current
V
BB
I
CEX
V
CE(SAT)
Operating, I
OUT
= ±1.5 A, L = 3 mH
V
OUT
= V
BB
V
OUT
= 0 V
Output Saturation Voltage
(Forward or Reverse Mode)
V
S
= 1.0 V:
Source Driver, I
OUT
= -0.85 A
Source Driver, I
OUT
= -1.5 A
Sink Driver, I
OUT
= 0.85 A
Sink Driver, I
OUT
= 1.5 A
Sense Current Offset
Clamp Diode Forward Voltage
(Sink or Source)
Motor Supply Current
(No Load)
I
SO
V
F
I
BB(ON)
I
BB(OFF)
D
0
= D
1
= D
2
= 0.8 V
I
S
- I
OUT
, I
OUT
= 850 mA,
V
S
= 0 V, V
CC
= 5 V
I
F
= 0.85 A
I
F
= 1.5 A
—
—
—
—
20
—
—
—
—
1.0
1.3
0.5
1.3
33
1.2
1.4
2.0
1.0
1.2
1.5
0.6
1.5
40
1.4
1.7
4.0
50
V
V
V
V
mA
V
V
mA
μA
V
CC
—
—
—
<1.0
<-1.0
50
50
-50
V
μA
μA
Continued next page…
Table 1 — PHASE Truth Table
PHASE
H
L
OUT
A
H
L
OUT
B
L
H
Table 3 — DAC Truth Table
DAC DATA
D
2
D
1
D
0
H
H
H
H
L
L
L
L
H
H
L
L
H
H
L
L
H
L
H
L
H
L
H
L
Current
Ratio, %
100
92.4
83.1
70.7
55.5
38.2
19.5
V
REF
/V
S
3.00
3.25
3.61
4.24
5.41
7.85
15.38
Table 2 — PFD Truth Table
V
PFD
≥3.5
V
1.1 V to 3.1 V
≤0.8
V
Description
Slow Current-Decay Mode
Mixed Current-Decay Mode
Fast Current-Decay Mode
All Outputs Disabled
where V
S
= I
TRIP
•R
S
. See Applications section.
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
3
ALLEGRO [ ALLEGRO MICROSYSTEMS ]
