Datasheet A3955 (Allegro) - 4

A3955 Full-Bridge PWM Microstepping Motor Driver ELECTRICAL CHARACTERISTICS at TA = 25°C, VBB = 5 V to 50 V, VCC = 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 VBB Operating, IOUT = ±1.5 A, L = 3 mH VCC — 50 V Output Leakage Current ICEX VOUT = VBB — <1.0 50 μA VOUT = 0 V — <-1.0 -50 μA Output Saturation Voltage VCE(SAT) VS = 1.0 V: (Forward or Reverse Mode) Source Driver, IOUT = -0.85 A — 1.0 1.2 V Source Driver, IOUT = -1.5 A — 1.3 1.5 V Sink Driver, IOUT = 0.85 A — 0.5 0.6 V Sink Driver, IOUT = 1.5 A — 1.3 1.5 V Sense Current Offset ISO IS - IOUT, IOUT = 850 mA, 20 33 40 mA VS = 0 V, VCC = 5 V Clamp Diode Forward Voltage VF IF = 0.85 A — 1.2 1.4 V (Sink or Source) IF = 1.5 A — 1.4 1.7 V Motor Supply Current IBB(ON) — 2.0 4.0 mA (No Load) IBB(OFF) D0 = D1 = D2 = 0.8 V — 1.0 50 μA Continued next page…
Table 3 — DAC Truth Table Table 1 — PHASE Truth Table PHASE OUTA OUTB DAC DATA Current D2 D1 D0 Ratio, % VREF/VS
H H L H H H 100 3.00 L L H H H L 92.4 3.25 H L H 83.1 3.61
Table 2 — PFD Truth Table
H L L 70.7 4.24
VPFD Description
L H H 55.5 5.41 ≥3.5 V Slow Current-Decay Mode L H L 38.2 7.85 1.1 V to 3.1 V Mixed Current-Decay Mode L L H 19.5 15.38 ≤0.8 V Fast Current-Decay Mode L L L All Outputs Disabled where VS = ITRIP•RS. See Applications section. Allegro MicroSystems, Inc. 3 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com