A4975 ALLEGRO [Allegro MicroSystems], A4975 Datasheet
A4975
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A4975 Summary of contents
Page 1
... V CC 4975-DS Description The A4975 is designed to drive one winding of a bipolar stepper motor in a microstepping mode. The outputs are rated for continuous output currents to ±1.5 A and operating voltages Internal pulse width modulated (PWM) current control combined with an internal three-bit nonlinear digital- to-analog converter allows the motor current to be controlled in full-, half-, quarter-, or eighth-step (microstepping) modes ...
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... Internal circuit protection includes thermal shutdown with hysteresis, an undervoltage monitor, and crossover-current protection. Special power-up sequencing is not required. The A4975 is supplied in a choice of two power packages; a 16-pin dual-in-line plastic package with copper heat-sink tabs (suffix ‘B’), Selection Guide Part Number ...
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... A4975 ELECTRICAL CHARACTERISTICS at T Characteristic Power Outputs Load Supply Voltage Range Output Leakage Current Output Resistance Motor Supply Current (No Load) Control Circuitry Logic Supply Voltage Range Reference Voltage Range UVLO Enable Threshold UVLO Hysteresis Logic Supply Current Logic Input Voltage Logic Input Current ...
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... A4975 Full-Bridge PWM Microstepping Motor Driver ELECTRICAL CHARACTERISTICS (continued 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 * The total error for the V /V function is the sum of the D/A error and the current-sense comparator input offset voltage ...
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... A4975 Full-Bridge PWM Microstepping Motor Driver Note the A4975SB (DIP) and the A4975SLB (SOIC) are electrically identical and share a common terminal number assignment. Terminal Name Description 1 PFD (Percent Fast Decay) The analog input used to set the current-decay mode. 2 REF ( The parallel combination of external resistor R PWM current regulator ...
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... To improve motor performance, especially when using sinusoidal current profi les necessary for microstepping, the A4975 has three distinct current-decay modes: slow decay, fast decay, and mixed decay. The PHASE input controls the direction of PHASE Input. current fl the load (table 1). An internally generated dead time of approximately 500 ns prevents crossover currents that could occur when switching the PHASE input ...
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... A4975 Full-Bridge PWM Microstepping Motor Driver performance in microstepping applications. For a given level of ripple current, slow decay affords the lowest PWM frequency, which reduces heating in the motor and driver IC due to a corresponding decrease in hysteretic core losses and switching losses respectively. Slow decay also has the advantage ...
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... A4975 Full-Bridge PWM Microstepping Motor Driver . If V Mixed Current-Decay Mode and 3.1 V, the device will mixed current-decay mode. Mixed-decay mode allows the user to achieve good current regulation with a minimum amount of ripple current and motor/driver losses by selecting the minimum percentage of fast decay required for their application (see also the Stepper Motor Applications section) ...
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... Figure 4 — Typical Application MIXED DECAY SLOW DECAY MIXED DECAY The A4975 is used to . When the load current is decreasing, the mixed OFF BRIDGE LOGIC SLOW DECAY Dwg ...
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... A4975 Full-Bridge PWM Microstepping Motor Driver Full Half Quarter Eighth Step Step Step Step ...
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... A4975 Full-Bridge PWM Microstepping Motor Driver A 100 92.4 83.1 70.7 55.5 38.2 19 19.5 38.2 55.5 70.7 CURRENT IN PER CENT Figure 5 — Current and Displacement Vectors MAXIMUM FULL-STEP FULL STEP B 83.1 92.4 100 Dwg. GK-020-1 Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 11 ...
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... A4975 Full-Bridge PWM Microstepping Motor Driver 1.27 MIN +0.25 1.52 –0.38 10.30±0. 16X 0.10 C 0.41 ±0.10 1.27 B package 16-pin DIP 19.05±0.25 +0.76 +0.38 6.35 10.92 –0.25 –0.25 For Reference Only 5.33 MAX (reference JEDEC MS-001 BB) Dimensions in millimeters +0.51 Dimensions exclusive of mold flash, gate burrs, and dambar protrusions 3.30 –0.38 Exact case and lead configuration at supplier discretion within limits shown 2 ...
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... A4975 Full-Bridge PWM Microstepping Motor Driver Revision History Revision Final Copyright ©2009-2011, Allegro MicroSystems, Inc. Allegro MicroSystems, Inc. reserves the right to make, from time to time, such de par tures from the detail spec tions as may be required to per- mit improvements in the per for mance, reliability, or manufacturability of its products. Before placing an order, the user is cautioned to verify that the information being relied upon is current. Allegro’ ...