Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Dual DMOS Full-Bridge
Microstepping PWM Motor Driver
A3972
5
ELECTRICAL CHARACTERISTICS at T
A
= +25°C, V
BB
= 50 V, V
DD
= 5.0 V, V
S
= 0.5 V,
f
PWM
< 50 kHz (unless otherwise noted).
Limits
Characteristics Symbol Test Conditions Min. Typ. Max. Units
Control Logic (continued)
Internal Oscillator f
OSC
OSC shorted to ground 3.0 4.0 5.0 MHz
R
OSC
= 51 k 3.4 4.0 4.6 MHz
DAC Accuracy (total error) E
T
Relative to DAC reference buffer
— ±1/2 — LSB
output, D0 = 0, D17 = 0
Reference Input Voltage Range V
REF(EXT)
0.5 — 2.6 V
Reference Buffer Offset V
OS
— ±10 — mV
Reference Divider Ratio V
REF
/V
S
D0 = 0, D18 = 0 — 8.0 — —
D0 = 0, D18 = 1 — 4.0 — —
Reference Input Current I
REF
V
REF
= 2.0 V — — ±0.5 μA
Internal Reference Voltage V
REF(INT)
1.94 2.0 2.06 V
Gain (G
m
) Error (note 3) E
G
D0 = 0, D17 = 0,
D18 = 0, DAC = 63 — 0 ±6 %
D18 = 0, DAC = 31 — 0 ±9 %
D18 = 1, DAC = 63 — 0 ±6 %
D18 = 1, DAC = 15 — 0 ±10 %
Comparator Input Offset Voltage V
IO
V
REF
= 0 V — ±5.0 — mV
Propagation Delay Times t
pd
50% to 90%:
PWM change to source on 500 800 1200 ns
PWM change to source off 50 150 350 ns
PWM change to sink on 500 800 1200 ns
PWM change to sink off 50 150 350 ns
Crossover Dead Time t
dt
300 700 900 ns
Thermal Shutdown Temperature T
J
— 165 — °C
Thermal Shutdown Hysteresis T
J
— 15 — °C
UVLO Enable Threshold V
UVLO
Increasing V
DD
3.9 4.2 4.45 V
UVLO Hysteresis V
UVLO
0.05 0.10 — V
NOTES: 1. Typical Data is for design information only.
2. Negative current is defi ned as coming out of (sourcing) the specifi ed device terminal.
3. E
G
= [(V
REF
/Range) – V
S
]/(V
REF
/Range).
