Allegro A3977 Microstepping DMOS Motor Driver IC, TSSOP-28

The Allegro A3977SLPTR-T is a high-performance, fully integrated microstepping motor driver with a built-in translator, designed for precise control of bipolar stepper motors. It operates from a 3V to 5.5V logic supply and is capable of driving motors with a 2.5A, 35V output rating, making it a versatile solution for a wide array of motion control applications.

This driver simplifies motor control by eliminating the need for complex programming. The integrated translator allows the motor to be driven one step at a time with a single pulse on the STEP input, removing the requirement for phase-sequence tables or high-frequency control lines. This makes it an ideal interface where a sophisticated microprocessor is either unavailable or its resources are already fully utilised.

Key Performance Features

• Advanced Current Control: A fixed off-time current regulator supports slow, fast, and mixed-decay modes. This intelligent current-decay control significantly reduces audible motor noise, improves step accuracy, and minimises power dissipation.
• High-Efficiency Design: Featuring low RDS(on) outputs (typically 0.28Ω source, 0.22Ω sink) and internal synchronous-rectification circuitry, the driver ensures excellent thermal performance and low power loss during PWM operation.
• Comprehensive Protection: Robust internal safeguards include thermal shutdown with hysteresis, under-voltage lockout (UVLO), and crossover-current protection, ensuring reliable operation and enhanced system durability.
• Flexible Microstepping: The driver supports multiple stepping modes, enabling operation in full, half, quarter, and eighth-step resolutions for smooth and precise motor movement.

Packaged in a space-saving TSSOP-28 format, this motor driver IC combines advanced functionality with reliable protection in a compact form factor, suitable for demanding embedded designs.