A3955SLBTR-T

Overview

The A3955SLBTR-T is a full-bridge PWM microstepping motor driver designed for bipolar stepper motors. It supports continuous output currents of ±1.5 A and operating voltages up to 50 V. The device integrates an internal three-bit nonlinear digital-to-analog converter (DAC) for current control, enabling full-, half-, quarter-, or eighth-step microstepping modes. Key features include internal pulse width modulated (PWM) current control, fast mixed fast/slow, and slow current-decay modes, internal transient-suppression diodes, thermal shutdown, crossover-current protection, and under-voltage lockout (UVLO).

Feature Summary

• Integrates a three-bit nonlinear DAC for precise microstepping current control.
• Supports multiple step resolutions including full, half, quarter, and eighth steps.
• Includes internal thermal shutdown and under-voltage lockout protection circuits.

Applications

• Bipolar stepper motor drives in microstepping mode
• General purpose motion control systems requiring high resolution
• Applications needing reduced torque variation and low-speed resonance

Procurement Notes

Verify the specific suffix 'SLBTR-T' against the manufacturer's latest datasheet to confirm package type, tape-and-reel specifications, and RoHS compliance status. Ensure the component meets the required operating temperature range and voltage ratings for the target application before finalizing procurement.

Selection Notes

Select this component when driving bipolar stepper motors with microstepping requirements. It is suitable for applications needing integrated current control and protection features without external discrete components. Consider the ±1.5 A current rating and 50 V voltage limit during system design.

Part Context

The A3955 belongs to Allegro MicroSystems' family of DMOS full-bridge microstepping motor drivers. It is designed to simplify the drive circuitry for bipolar stepper motors by integrating power stages, control logic, and protection features into a single IC.

Replacement Considerations

A3957SLBTR-T offers similar functionality with different current/voltage characteristics. Verify pin compatibility and electrical specifications before substitution.

FAQ

What microstepping resolutions are supported?

The A3955 supports full-step, half-step, quarter-step, and eighth-step microstepping modes via its internal three-bit nonlinear DAC.

Does the device include protection features?

Yes, it includes internal thermal shutdown, crossover-current protection, and under-voltage lockout (UVLO).