A4975
Full-Bridge PWM Microstepping Motor Driver
ELECTRICAL CHARACTERISTICS (continued) at TA = 25°C, VCC = 4.5 to 5.5 V (unless
otherwise noted.)
Characteristic
Control Circuitry (cont’d)
Current-Sense Comparator Input
Offset Voltage*
Step Reference Current Ratio
Thermal Shutdown Temp.
Thermal Shutdown Hysteresis
AC Timing
PWM RC Fixed Off-time
PWM Minimum On Time
Symbol Test Conditions
VIO(S)
SRCR
TJ
∆TJ
VREF = 0 V
D0 = D1 = D2 = VIN(0)
D0 = VIN(1), D1 = D2 = VIN(0)
D0 = VIN(0), D1 = VIN(1), D2 = VIN(0)
D0 = D1 = VIN(1), D2 = VIN(0)
D0 = D1 = VIN(0), D2 = VIN(1)
D0 = VIN(1), D1 = VIN(0), D2 = VIN(1)
D0 = VIN(0), D1 = D2 = VIN(1)
D0 = D1 = D2 = VIN(1)
tOFFRC
tON(min)
CT = 470 pF, RT= 43 kΩ
VCC = 5.0 V, RT ≥ 43 kΩ, CT = 470 pF,
IOUT = 100 mA
Min.
Typ. Max. Unit
—
—
±5.0
mV
—
0
—
%
—
19.5
—
%
—
38.2
—
%
—
55.5
—
%
—
70.7
—
%
—
83.1
—
%
—
92.4
—
%
—
100
—
%
—
165
—
°C
—
15
—
°C
18.2
20.2
22.3
μs
0.8
1.6
2.2
μs
* The total error for the VREF/VS function is the sum of the D/A error and the current-sense comparator input offset voltage.
Table 1 — PHASE Truth Table
PHASE
OUTA
OUTB
H
H
L
L
L
H
Table 2 — PFD Truth Table
VPFD
≥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
Table 3 — DAC Truth Table
DAC DATA
D2
D1
D0
Current
Ratio, %
VREF/VS
H
H
H
100
5.00
H
H
L
92.4
5.41
H
L
H
83.1
6.02
H
L
L
70.7
7.07
L
H
H
55.5
9.01
L
H
L
38.2
13.09
L
L
H
19.5
25.64
L
L
L
All Outputs Disabled
where VS = ITRIP×RS. See Applications section.
Allegro MicroSystems, Inc.
4
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com