DS21T05Z

Overview

The DS21T05Z is a SCSI terminator IC compliant with SCSI-1, Fast SCSI, and Ultra SCSI standards. It provides active termination for nine signal lines using laser-trimmed 110-ohm resistors with 5% tolerance. The device operates on a TERMPWR supply voltage ranging from 4.0V to 5.5V. It features a low dropout regulator and integrates onboard thermal shutdown circuitry. The component is housed in a 16-pin plastic narrow SOIC package and supports an operating temperature range of 0°C to +70°C.

Feature Summary

• Provides active termination for nine SCSI signal lines with integrated regulation
• Supports hot-plug operations without affecting the SCSI bus
• Includes power-down mode to isolate termination resistors from the bus

Applications

• Active termination at cable ends in SCSI systems with single-ended drivers
• Disk drive integration within RAID system components
• Peripheral devices acting as targets on a SCSI bus

Procurement Notes

Verify the specific ordering suffix against official documentation to confirm package dimensions and pinout compatibility. Confirm RoHS compliance status and environmental declarations prior to procurement. Ensure that the source document explicitly identifies the manufacturer and part number to avoid substitution errors during acquisition.

Selection Notes

Select this component for high-volume applications requiring active termination where relaxed output current and termination tolerances are acceptable. It serves as a functionally compatible alternative to the DS21T07 but lacks its high-performance specifications. Ensure the design accommodates the required external decoupling capacitors for the VREF pins.

Part Context

The DS21T05Z belongs to the DS21T05 series of SCSI terminators manufactured by Analog Devices Inc./Maxim Integrated. It is designed to replace discrete termination networks, offering a monolithic solution that simplifies PCB layout. The 'Z' suffix typically denotes lead-free packaging compliant with environmental directives.

Replacement Considerations

The DS21T07 is identified as a functionally compatible high-performance version. Verify electrical parameter differences before substituting.