A3977KED

Overview

The A3977KED is a complete microstepping motor driver with an integrated translator, designed for bipolar stepper motors. It supports full-, half-, quarter-, and eighth-step modes with output drive capabilities of 35 V and ±2.5 A. The device features a fixed off-time current regulator capable of slow-, fast-, or mixed-decay modes to reduce audible noise and power dissipation. It operates on a 3.0 to 5.5 V logic supply voltage range and includes synchronous rectification, internal UVLO, thermal shutdown, and crossover-current protection.

Feature Summary

• Integrated translator for direct step/direction control in multiple microstep resolutions
• Automatic current decay mode detection and selection for optimized performance
• Synchronous rectification architecture to minimize power dissipation
• Built-in protection mechanisms including thermal shutdown and crossover-current prevention

Applications

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

Procurement Notes

Verify the specific package variant, as the A3977KED typically denotes the PLCC-44 configuration. Confirm RoHS compliance status against the latest manufacturer datasheet, as older revisions may differ from current production standards. Ensure the design accounts for the required load voltage range of 8V to 35V separate from the logic supply.

Selection Notes

Select this component when a fully integrated solution with built-in translation is required to simplify PCB layout. It is suitable for applications needing reduced audible noise through automatic decay mode selection. Verify that the 2.5A output rating meets the motor's peak current requirements and that the PLCC-44 package fits the available board space.

Part Context

The A3977KED belongs to the Allegro A3977 family of microstepping DMOS drivers. This series provides a comprehensive solution for driving bipolar stepper motors by combining logic control and power stages in a single IC. The KED suffix specifically identifies the 44-pin PLCC package variant within this product line.

Replacement Considerations

The A3977SLPTR-T is documented as a similar alternative offering comparable functionality in a TSSOP-28 package. Designers must account for pinout differences and thermal management changes when substituting between the PLCC and TSSOP form factors.