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 DS21T07 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 DS21T07 integrates a regulator and nine precise switched 110 ohms termination resistors into a monolithic IC. The DS21T07 can be electrically isolated from the SCSI bus without physical removal from the SCSI device.

FEATURES

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

■ Backward compatible to the DS2107, DS2107A, and DS21S07

■ Provides active termination for nine signal lines

■ Laser–trimmed 110 ohms termination resistors have 2 tolerance

■ Low dropout voltage regulator

■ 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 SOIC (DS21T07S) and 20–pin plastic TSSOP (Thin Shrink Small Outline Package) (DS21T07E)