SI-7321M

Overview

The SI-7321M is a unipolar 2-phase stepper motor driver IC manufactured by Sanken Electric. It operates within a voltage range of 3V to 5.5V and utilizes a 44-HSOP package with four heat tabs for surface mount mounting. The device integrates self-excitation PWM current control with fixed off-time functionality, designed to regulate coil currents efficiently. It supports brushed DC motors in addition to its primary stepper motor applications.

Feature Summary

• Integrates self-excitation PWM current control with fixed off-time for precise regulation
• Includes built-in protection circuits for detecting coil short circuits and open lines
• Designed for unipolar 2-phase stepper motor driving applications

Applications

• Unipolar 2-phase stepper motor control systems
• Brushed DC motor driving circuits
• Automated equipment requiring microstepping capabilities

Procurement Notes

Verify the specific ordering suffix against official Sanken documentation to ensure correct package variant and temperature grade. Confirm that the 44-HSOP footprint matches your PCB design, particularly noting the four integrated heat tabs which require appropriate thermal management on the substrate. Ensure compatibility with the required supply voltage range of 3V to 5.5V for your system architecture.

Selection Notes

Select this component when designing systems requiring integrated PWM current control without external timing components. The built-in fault detection for coil shorts and opens reduces the need for additional monitoring circuitry. Consider the thermal performance requirements due to the HSOP package with heat tabs, ensuring adequate copper area for dissipation during continuous operation at specified load currents.

Part Context

This part belongs to Sanken's PMIC Motor Drivers, Controllers family. It is specifically categorized as a Unipolar Motor Driver Power IC. The manufacturer lists it as an active product, indicating ongoing production support. It serves as a dedicated solution for driving 2-phase stepper motors using unipolar configurations, distinguishing it from bipolar or hybrid driver alternatives.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided source material. Verify pin-to-pin compatibility and electrical specifications with alternative drivers from other manufacturers if sourcing constraints exist. Consult official Sanken documentation for any recommended cross-reference parts before implementation.