A4985SETTR-T

Overview

The A4985SETTR-T is a complete microstepping motor driver manufactured by Allegro MicroSystems, designed for driving bipolar stepper motors. It integrates a translator, current control, and power stage in a single DMOS solution. The device supports full, half, quarter, and eighth-step resolutions. It operates with a logic supply voltage range of 3V to 5.5V and a load voltage range of 8V to 35V. The maximum output current is rated at 1A. The component is housed in a 32-QFN (5x5mm) package with an exposed pad for thermal management. It functions within an ambient temperature range of -20°C to +85°C.

Feature Summary

• Integrates a built-in translator for simplified interface requiring only step and direction signals
• Features fixed off-time current regulator supporting slow or mixed decay modes for smooth operation
• Includes comprehensive protection mechanisms such as thermal shutdown, cross-current protection, and short-to-ground protection

Applications

• Bipolar stepper motor control systems
• General motion control applications
• Industrial automation devices
• Office automation equipment

Procurement Notes

Verify the specific suffix 'SETTR-T' corresponds to the 32-QFN package variant when sourcing. Confirm that the required output current does not exceed the 1A rating without external heat sinking. Ensure logic levels match the 3V-5.5V input specification. Check moisture sensitivity level handling requirements during assembly. Validate that the application environment stays within the specified operating temperature range.

Selection Notes

Select this component for applications requiring integrated microstepping control with minimal external circuitry. It is suitable for designs needing quarter or eighth-step resolution with a 1A current limit. Consider the 32-QFN package for space-constrained PCB layouts. Ensure the system can provide adequate thermal dissipation given the exposed pad design. Verify compatibility with the available logic voltage levels before integration.

Part Context

This part belongs to the A4985 family of microstepping drivers from Allegro MicroSystems. It shares functional similarities with other members like the A4985SESTR-T but differs in packaging. The SETTR-T variant specifically utilizes a 32-pin QFN form factor compared to the 24-pin options in the same series. It represents a compact solution for low-power stepper motor applications.

Replacement Considerations

The A4985SESTR-T serves as a pin-compatible alternative within the same family but utilizes a 24-QFN package instead of the 32-QFN. Designers must verify footprint changes if substituting between these variants. Other A49xx family members may offer different current ratings or step resolutions.