DS21T05

DS21T05 SCSI Terminator www.dalsemi.com FEATURES PIN ASSIGNMENT Fully compliant with SCSI-1, Fast SCSI and Ultra SCSI 16 1 PD TERMPWR1 Functionally compatible to the DS21T07, 15 2 R1 VREF2 targeted for high volume applications 14 3 R2 R9 R8 4 13 Provides active termination for nine signal R3 12 5 R4 R7 lines 11 6 R5 R6 Laser-trimmed 110-ohm termination resistors 10 7 VREF1 NC have 5% tolerance 9 8 GND TERMPWR2 Low dropout voltage DS21T05Z 16-Pin SOIC (150-mil) Power-down mode isolates termination resistors from the bus PD TERMPWR1 1 16 SCSI bus hot-plug compatible R1 VREF2 2 15 Fully supports actively negated SCSI signals R2 NC 3 14 Onboard thermal shutdown circuitry R9 R3 4 16-pin plastic narrow SOIC 13 R4 R5 VREF1 GND 5 6 7 8 12 11 10 9 R8 R7 R6 TERMPWR2 DS21T05S 16-Pin SOIC (300-mil) 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...