DS2120B/T&R

Overview

The DS2120B/T&R is an Ultra3 LVD SCSI terminator manufactured by Analog Devices Inc./Maxim Integrated. It provides low-voltage differential termination for nine signal line pairs in a 36-pin SSOP package with tape and reel packaging. The device operates at 5V within a 0°C to +70°C temperature range. Key electrical parameters include a typical differential mode termination resistance of 110 Ω, common mode termination resistance of 190 Ω, and output capacitance of 3pF. It features a built-in mode change delay of up to 1.25 ms and thermal shutdown protection at 150°C.

Feature Summary

• Fully compliant with Ultra3, Ultra160, Ultra320, and Ultra2 (LVD only) SCSI standards
• Integrates laser-trimmed resistors with zero temperature coefficient for precision termination
• Automatically detects bus conditions via DIFFSENSE to isolate from SE or HVD devices
• Includes on-board thermal shutdown circuitry and digital noise filtering for the DIFFSENS line

Applications

• Raid Systems
• SCSI Host Bus Adapter Cards (HBA)
• Servers
• Network Attached Storage (NAS)
• Storage Area Networks (SANs)

Procurement Notes

Verify component authenticity through authorized distributors or direct manufacturer channels. Confirm the specific ordering suffix matches the required tape and reel configuration. Check for RoHS compliance status as indicated by the datasheet documentation. Ensure the supply chain source provides valid traceability records for quality assurance purposes.

Selection Notes

Select this component for Ultra3 LVD SCSI applications requiring automatic mode detection. Ensure the design accommodates the 36-pin SSOP footprint and tape and reel handling requirements. Verify that the system power supply meets the 5V operating voltage specification. Consider the thermal management needs given the internal shutdown threshold.

Part Context

This part belongs to the DS2120 family of Ultra3 LVD SCSI terminators. It shares functional similarities with the DS2119ME+ but utilizes a different package and pin count. The T&R suffix indicates tape and reel packaging suitable for automated assembly processes. It serves as a critical interface component for maintaining signal integrity in high-speed SCSI buses.

Replacement Considerations

DS2120E/T&R is a verified alternative offering the same functionality in a 28-TSSOP package.