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A3969 Datasheet(PDF) 1 Page - Allegro MicroSystems |
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A3969 Datasheet(HTML) 1 Page - Allegro MicroSystems |
1 / 9 page ![]() Description The A3969 is designed to drive both windings of a two-phase bipolar stepper motor. The device includes two H-bridges capable of continuous output currents of ±650 mAand operating voltages to 30 V. Motor winding current can be controlled by the internal fixed-frequency, pulse-width modulated (PWM), current-control circuitry. The peak load current limit is set by the user’s selection of a reference voltage and current-sensing resistors. The fixed-frequency pulse duration is set by a user-selected external RC timing network. The capacitor in the RC timing network also determines a user-selectable blanking window that prevents false triggering of the PWM current-control circuitry during switching transitions. To reduce on-chip power dissipation, the H-bridge power outputs have been optimized for low saturation voltages. The sink drivers feature the Allegro® patented Satlington® output structure. The Satlington outputs combine the low voltage drop of a saturated transistor and the high peak current capability of a Darlington. DS3969 Features and Benefits ▪ ±650 mA Continuous Output Current ▪ 30 V Output Voltage Rating ▪ Internal Fixed-Frequency PWM Current Control ▪ Satlington Sink Drivers ▪ User-Selectable Blanking Window ▪ Internal Ground-Clamp and Flyback Diodes ▪ Internal Thermal-Shutdown Circuitry ▪ Crossover-Current Protection and UVLO Protection Dual Full-Bridge PWM Motor Driver Continued on the next page… Package: 28 pin QFN (suffix ET) Typical Application Approximate scale A3969 Continued on the next page… 21 20 19 18 17 16 15 1 2 3 4 5 6 7 LOGIC LOGIC VBB 0.5 Ω 0.5 Ω 56 kΩ 10 kΩ 20 kΩ EN1 EN2 PH1 PH2 +3.3 V +3.3 V +24 V 47 μF 680 pF |