Datasheet A4975 (Allegro) - 5

A4975 Full-Bridge PWM Microstepping Motor Driver ELECTRICAL CHARACTERISTICS (continued): Valid at TA = 25°C, VCC = 4.5 to 5.5 V, unless otherwise noted Characteristic Symbol Test Conditions Min. Typ. Max. Unit CONTROL CIRCUITRY (continued)
Current-Sense Comparator Input Offset Voltage* VIO(S) VREF = 0 V — — ±5.0 mV D0 = D1 = D2 = VIN(0) — 0 — % D0 = VIN(1), D1 = D2 = VIN(0) — 19.5 — % D0 = VIN(0), D1 = VIN(1), D2 = VIN(0) — 38.2 — % D Step Reference Current Ratio SRCR 0 = D1 = VIN(1), D2 = VIN(0) — 55.5 — % D0 = D1 = VIN(0), D2 = VIN(1) — 70.7 — % D0 = VIN(1), D1 = VIN(0), D2 = VIN(1) — 83.1 — % D0 = VIN(0), D1 = D2 = VIN(1) — 92.4 — % D0 = D1 = D2 = VIN(1) — 100 — % Thermal Shutdown Temperature TJ — 165 — °C Thermal Shutdown Hysteresis ∆TJ — 15 — °C
AC TIMING
PWM RC Fixed Off-Time tOFFRC CT = 470 pF, RT= 43 kΩ 18.2 20.2 22.3 µs PWM Minimum On-Time t VCC = 5.0 V, RT ≥ 43 kΩ, CT = 470 pF, ON(min) IOUT = 100 mA 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 Table 3 — DAC Truth Table PHASE OUTA OUTB DAC DATA Current D2 D1 D0 Ratio, % VREF/VS
H H L L L H H H H 100 5.00 H H L 92.4 5.41
Table 2 — PFD Truth Table
H L H 83.1 6.02 H L L 70.7 7.07
VPFD Description
L H H 55.5 9.01 ≥3.5 V Slow Current Decay Mode L H L 38.2 13.09 1.1 V to 3.1 V Mixed Current Decay Mode L L H 19.5 25.64 ≤0.8 V Fast Current Decay Mode L L L All Outputs Disabled where VS = ITRIP×RS. See Applications section. Allegro MicroSystems, LLC 5 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com