DESCRIPTION

Fast SCSI and Ultra SCSI require the use of active terminations at both ends of every cable segment in a SCSI system with single-ended drivers and receivers. The DS21T05 SCSI Terminator, which is fully compliant with these standards, enables the designer to gain the benefits of active termination: greater immunity to voltage drops on the TERMPWR (TERMination PoWeR) line, enhanced high-level noise immunity, intrinsic TERMPWR decoupling, and very low quiescent current consumption. The DS21T05, which integrates a regulator and nine precise-switched, 110-ohm termination resistors into a monolithic IC, is a functionally compatible version of the DS21T07. With relaxed output current and termination tolerances, the DS21T05 is intended for high volume applications which require active termination but not the high performance of the DS21T07.

FEATURES

■ Fully compliant with SCSI-1, Fast SCSI and Ultra SCSI

■ Functionally compatible to the DS21T07, targeted for high volume applications

■ Provides active termination for nine signal lines

■ Laser-trimmed 110-ohm termination resistors have 5 tolerance

■ Low dropout voltage

■ Power-down mode isolates termination resistors from the bus

■ SCSI bus hot-plug compatible

■ Fully supports actively negated SCSI signals

■ Onboard thermal shutdown circuitry

■ 16-pin plastic narrow SOIC