DS21T07E/T&R

Overview

The DS21T07E/T&R is a SCSI terminator IC in a 20-pin TSSOP package. It provides active termination for nine signal lines compliant with SCSI-1, Fast SCSI, and Ultra SCSI standards. The device integrates laser-trimmed 110 ohm termination resistors with 2% tolerance and a low dropout voltage regulator. Operating conditions include a TERMPWR voltage range of 4.00V to 5.50V and an operating temperature of 0°C to 70°C. Power-down current is typically 150µA when the PD pin is low.

Feature Summary

• Fully compliant with SCSI-1, Fast SCSI, and Ultra SCSI standards
• Integrates nine precise switched 110 ohm termination resistors
• Includes onboard thermal shutdown circuitry
• Supports SCSI bus hot-plug operations via power-down mode

Applications

• Active termination at both ends of cable segments in SCSI systems
• Integration into disk drives requiring SCSI connectivity
• Termination for RAID system components

Procurement Notes

Verify component authenticity through authorized distributors or direct manufacturer channels. Confirm RoHS compliance status as datasheets may vary by production batch. Check for obsolescence notices from Analog Devices or Maxim Integrated before procurement planning.

Selection Notes

Select this component for designs requiring active termination for up to nine SCSI signal lines. Ensure the design accommodates the 20-pin TSSOP footprint. Verify that the system TERMPWR line falls within the 4.00V to 5.50V operating range.

Part Context

This part belongs to the DS21T07 family of SCSI terminators. It serves as an upgrade to earlier models like the DS2107 and DS21S07, offering backward compatibility while supporting higher speed SCSI standards. The 'E' suffix denotes the 20-pin TSSOP package variant.

Replacement Considerations

The DS21T07S is the 16-pin SOIC equivalent. Earlier generations such as the DS2107, DS2107A, and DS21S07 are backward compatible but lack full Ultra SCSI support.