A3964SB

Overview

The A3964SB is a fully integrated bipolar stepper motor driver manufactured by Allegro MicroSystems. It combines control logic, an oscillator, a current regulator, and a high-current H-bridge power stage into a single DMOS IC. The device supports full, half, quarter, and eighth-step microstepping resolutions via three digital inputs. It operates with a supply voltage range of 4.75V to 5.25V and drives loads between 5V and 30V. The output current capability is rated at 800mA. It utilizes a 20-SOIC package with a junction temperature operating range from -20°C to 150°C.

Feature Summary

• Integrates control logic, oscillator, current regulation, and power stage for simplified design
• Supports multiple stepping modes including full, half, quarter, and eighth-step microstepping
• Features adjustable current limit with constant-on-time PWM chopper control
• Includes thermal shutdown and undervoltage lockout protection mechanisms

Applications

• Office automation equipment such as printers and scanners
• Automotive instrument clusters and displays
• General-purpose bipolar stepper motor control systems

Procurement Notes

Verify the specific suffix 'SB' against the manufacturer's official datasheet to confirm pinout compatibility and electrical specifications. Confirm RoHS status and lifecycle status, as older Allegro parts may have discontinued variants or alternative packaging options available from authorized distributors.

Selection Notes

Select this component when a compact solution for driving bipolar stepper motors is required without external discrete drivers. Ensure the application load current remains within the 800mA limit and that the supply voltage aligns with the specified 5V nominal range. Consider thermal management requirements given the SOIC package and operating temperature range.

Part Context

The A3964 belongs to Allegro's family of fully integrated bipolar stepper motor drivers. These devices are designed to replace complex discrete driver circuits. The A3964 series is commonly used in applications requiring precise motion control with minimal external components, leveraging Allegro's DMOS technology for efficient power handling.

Replacement Considerations

Check for direct replacements such as the A3964SLBTR or other A3964 variants with different suffixes that may offer updated packaging or compliance status. Verify functional equivalence regarding pinouts and electrical ratings before substitution.