A4975SB-T

Overview

The A4975SB-T is a full-bridge PWM microstepping motor driver designed for bipolar stepper motors. It features continuous output currents of ±1.5 A and supports operating voltages up to 50 V. The device integrates internal pulse width modulated (PWM) current control with a three-bit nonlinear digital-to-analog converter, enabling full-, half-, quarter-, or eighth-step microstepping modes. It operates within a supply voltage range of 4.5 V to 5.5 V and includes fast, mixed, and slow current-decay modes. The component utilizes PowerSOIC-16 packaging.

Feature Summary

• Integrates internal PWM current control with a three-bit nonlinear DAC for precise microstepping resolution
• Provides fast, mixed fast/slow, and slow current-decay modes for optimized motor performance
• Includes internal thermal shutdown circuitry and crossover-current protection

Applications

• Bipolar stepper motor drives in microstepping mode
• General-purpose motion control systems requiring integrated power and control
• Applications necessitating reduced torque variations and resonance problems at low speeds

Procurement Notes

Verify the specific package type against project requirements, as the A4975 family includes both SOIC and DIP variants. Confirm that the 4.5 V to 5.5 V logic supply range aligns with the system's voltage rails. Ensure the ±1.5 A current rating and 50 V voltage limit are sufficient for the target motor winding specifications. Check for RoHS3 compliance status if required by regional regulations.

Selection Notes

Select this component when a fully integrated solution for bipolar stepper motors is required without external power MOSFETs. The internal nonlinear DAC simplifies microstepping implementation by minimizing control lines. Consider the thermal management capabilities provided by the internal shutdown circuitry. Evaluate the need for specific current-decay modes to match the mechanical characteristics of the driven load.

Part Context

The A4975 belongs to Allegro Microsystems' A49xx family of stepper motor driver ICs. This series focuses on providing complete drive solutions with integrated control logic and power stages. The A4975 specifically targets applications requiring high-resolution microstepping and robust protection features within a compact footprint.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.