A3986 Allegro Micro Systems, Inc., A3986 Datasheet
A3986
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A3986 Summary of contents
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... Rev. 1 Dual Full-Bridge MOSFET Driver with Microstepping Translator Description The A3986 is a dual full-bridge gate driver with integrated microstepping translator suitable for driving a wide range of higher power industrial bipolar 2-phase stepper motors (typically 30 to 500 W). Motor power is provided by external N-channel power MOSFETs at supply voltages from ...
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... Selection Guide Part Number A3986SLD-T Tube, 50 pieces per tube A3986SLDTR-T Tape and reel, 4000 pieces per reel *Contact Allegro for additional packing options Absolute Maximum Ratings Characteristic Supply Voltage Logic Supply Voltage ...
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... A3986 +5 V VDD Bandgap V REF REF STEP DIR MS1 MS2 Translator PFD1 PFD2 ENABLE RESET SR OSC V ROSC Protection UVLO TSD Dual Full-Bridge MOSFET Driver with Microstepping Translator Functional Block Diagram VBB Regulator V REG Phase 1A High-Side Drive V REG DAC Low-Side Drive PWM Latch ...
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... A3986 ELECTRICAL CHARACTERISTICS at T Characteristics Supply and Reference Load Supply Voltage Range Load Supply Current Load Supply Idle Current Logic Supply Voltage Range Logic Supply Current Logic Supply Idle Current Regulator Output Bootstrap Diode Forward Voltage Gate Output Drive Turn-On Rise Time ...
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... A3986 ELECTRICAL CHARACTERISTICS, continued Characteristics Current Control Blank Time Fixed Off-Time Reference Input Voltage Internal Reference Voltage Current Trip Point Error 3 Reference Input Current 1 Oscillator Frequency Protection VREG Undervoltage Lockout VREG Undervoltage Lockout Hysteresis VDD Undervoltage Lockout VDD Undervoltage Lockout ...
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... A3986 THERMAL CHARACTERISTICS Characteristic Package Thermal Resistance *Additional thermal information available on Allegro Web site. RESET STEP MSx, DIR Figure 1. Logic Interface Timing Diagram Table 1. Microstep Resolution Truth Table MS2 MS1 Microstep Resolution Sixteenth Step Dual Full-Bridge MOSFET Driver ...
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... A3986 Table 3. Step Sequencing Settings Home microstep position at Step Angle 45º; DIR = H Full Half 1/4 1/16 Phase 2 Step Step Step Step Current (#) (#) (#) (#) (% I TRIP(max 18.75 4 29. 37.50 6 46.88 7 56.25 8 64. 70.31 10 76.56 11 82.81 12 87. 92.19 14 95.31 15 98.44 16 100. 100.00 18 100.00 19 98.44 20 95. 92.19 22 87.50 23 82.81 24 76. ...
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... A3986 STEP 100 71 I (%*) OUT1B Phase = 1, 0 Direction = H –71 –100 100 71 I (%*) OUT2B Phase = 2, 0 Direction = H –71 –100 *For precise definition of output levels, refer to table 3 Figure 2. Decay Mode for Full-Step Increments STEP I (%*) OUT1B Phase = 1, Direction = H –100 I (%*) OUT2B Phase = 2, Direction = H –100 *For precise definition of output levels, refer to table 3 Figure 4 ...
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... A3986 STEP 100 (%*) 10 OUT1B Phase = 1, 0 Direction = H –10 –20 –29 –38 –47 –56 –63 –71 –77 –83 –88 –96 –100 100 (%*) Slow OUT2B 10 Phase = 2, Direction = H 0 –10 –20 –29 – ...
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... The master oscillator period is used to derive the PWM off- time, dead time, and blanking time. Gate Drive The A3986 is designed to drive external power N-channel MOSFETs. It supplies the transient currents necessary to quickly charge and discharge the external FET gate capaci- tance in order to reduce dissipation in the external FET during switching ...
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... A3986 C1A, C1B, C2A, and C2B High-side connections for the bootstrap capacitors, CBOOTx, and positive supply for high- side gate drivers. The bootstrap capacitors are charged to approximately V when the associated output Sxx terminal REG is low. When the output swings high, the voltage on this ter- minal rises with the output to provide the boosted gate volt- age needed for the high-side N-channel power MOSFETs ...
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... OFF When the phase current is rising, the motor back EMF will not affect the current control and slow decay may be used to minimize the phase current ripple. The A3986 automatically switches between slow decay, when the current is rising, and , is 3 cycles of the mixed decay, when the current is falling ...
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... STEP input signal commands an output current that is lower than for the previous step. In mixed decay mode, as the trip point is reached, the A3986 goes into fast decay mode until the specified number of master oscillator cycles has completed. After this fast decay portion, the A3986 ...
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... All drivers are turned off when the junction temperature reaches 165°C typical. This is intended only to protect the A3986 from failures due to excessive junction temperatures. Thermal protection will not protect the A3986 from continu- ous short circuits. Thermal shutdown has a hysteresis of approximately 15°C. ...
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... A3986 Pin-out Diagram Terminal List Table Number Dual Full-Bridge MOSFET Driver with Microstepping Translator C2A 1 38 C2B GH2A 2 37 GH2B S2A 3 36 ...
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... A3986 38X 0.10 [.004] C 0.27 .011 38X 0.17 .007 0.08 [.003 0.30 .012 1.85 .073 NOM NOM Copyright ©2005, 2007, Allegro MicroSystems, Inc. The products described here are manufactured under one or more U.S. patents or U.S. patents pending. 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 ...