A3992SB-T

Overview

The A3992SB-T is a DMOS microstepping dual full-bridge PWM motor driver manufactured by Allegro MicroSystems. It features a ±1.5A maximum output current and supports load voltages from 15V to 50V. The logic supply voltage operates within a 4.5V to 5.5V range, with a typical nominal value of 5V. The device integrates low RDS(on) DMOS outputs, offering a typical on-resistance of 0.54Ω and a maximum of 0.6Ω. It includes an internal 4MHz oscillator for digital timing and synchronous rectification to reduce power consumption. Protection mechanisms include short-circuit protection, thermal shutdown, and cross-conduction prevention. The component is available in 24-pin batwing DIP (suffix B) and 24-pin TSSOP packages with exposed thermal pads.

Feature Summary

• Integrates low RDS(on) DMOS output drivers with synchronous rectification capabilities
• Supports programmable mixed/fast/slow current decay modes via serial interface
• Includes built-in protection against short circuits, thermal overload, and cross-conduction

Applications

• Microcontroller-controlled stepper motor drive systems
• General purpose bipolar stepper motor control applications
• Industrial automation equipment requiring precise motion control

Procurement Notes

Verify the obsolete status of this component before design finalization, as it may no longer be in active production. Confirm package availability for both the 24-pin batwing DIP and TSSOP options. Ensure that the required lead times align with project schedules given the end-of-life status. Check for RoHS compliance documentation if environmental regulations apply to the target market. Validate that alternative sources can provide genuine units to avoid counterfeit risks.

Selection Notes

Select this driver when a fully integrated solution for bipolar stepper motors is required without external power transistors. Consider the thermal resistance values based on the PCB layer count, as heat dissipation varies between 2-layer and 4-layer designs. Ensure the system logic voltage matches the 4.5V to 5.5V input range. Evaluate the need for sleep and idle modes if power efficiency during non-operational periods is critical for the application.

Part Context

This component belongs to Allegro MicroSystems' portfolio of highly integrated mixed-signal ICs designed for motor control and magnetic sensing. The A3992 series represents a line of DMOS-based drivers aimed at simplifying stepper motor implementation. Allegro specializes in solutions for automotive, industrial, and consumer markets, focusing on reducing component count and enhancing system reliability through advanced semiconductor technologies.

Replacement Considerations

Publicly confirmed substitute part numbers include A3972SB and A3992SLPTR-T. Verify pin compatibility and electrical specifications before substitution.