UCC5622MWP

Overview

The UCC5622MWP is a 27-line active terminator designed for SCSI parallel buses, compliant with SCSI, SCSI-2, SCSI-3, SPI, and FAST-20 standards. It operates within a 4V to 7V supply range and features split disconnect control: DISCNCT1 manages lines 10–27, while DISCNCT2 controls lines 1–9. The device provides 110Ω termination impedance trimmed to 5% accuracy and maintains a low channel capacitance of 2.5pF during disconnect. Supply current drops to 100µA in power-down mode. It supports -900mA sourcing and +500mA sinking currents, includes thermal shutdown at 170°C, and utilizes a 44-pin SSOP package.

Feature Summary

• Split disconnect architecture allows independent control of termination lines 1–9 and 10–27 via dedicated logic inputs.
• Low channel capacitance of 2.5pF preserves signal integrity by minimizing effects from disconnected terminators on the bus.
• Internal circuit trimming ensures precise 110Ω impedance matching and optimized output current for maximum noise margin.
• Integrated protection mechanisms include current limiting and thermal shutdown to safeguard against fault conditions.

Applications

• High-performance 5V SCSI systems requiring active termination at both cable ends.
• FAST-20 (Ultra) SCSI bus implementations needing precise impedance control.
• Systems requiring hot-pluggable termination components that appear as high impedance when powered down.

Procurement Notes

Verify the specific ordering suffix to confirm packaging quantity and environmental compliance. The MWP suffix indicates a 44-pin SSOP package. Confirm RoHS status and lead finish details through official Texas Instruments documentation or authorized distributors before finalizing procurement orders.

Selection Notes

Select this component for applications requiring a 27-line active terminator with split disconnect functionality. Ensure the design accommodates the 4V to 7V operating voltage range and the 44-pin SSOP footprint. Verify that the system requires the specific -900mA sourcing and +500mA sinking capabilities defined in the electrical characteristics.

Part Context

The UCC5622 is part of the Unitrode terminator family, designed specifically for SCSI bus architectures. It replaces passive termination resistors to reduce power consumption during disconnect states. The device integrates an internal regulator and protection circuits, simplifying the design of wide SCSI bus configurations compared to discrete resistor networks.

Replacement Considerations

Consult the Texas Instruments Product Change Notification (PCN) database for verified substitute part numbers. No direct cross-model substitutes are listed in the provided datasheet; verify compatibility with legacy designs using the connection diagram and pin descriptions.