DESCRIPTION

The SCSI-2 and SCSI-3 standards recommend the use of active terminations at both ends of every cable segment in a SCSI system with a single-ended drivers and reveivers. The ST21S07A SCSI terminator, which is fully compliant with these standands, enables the designer to gain the benefits of active termination: greater immunity to voltages drop on the TERMPWR (TERMination PoWeR) line, enhanced high level noise immunity, intrinsic TERMPWR decouplig, and very low quiescent current consumption.

The ST21S07A integrates a regulator and nine precise switched 110Ω termination resistors into a monolithic IC. The ST21S07A can be electrically isolatesd from the SCSI bus without physical removal from the SCSI device.

■ FULLY COMPLIANT WITH SCSI, SCSI-2 AND EMERGING SCSI-E STANDARDS

■ PROVIDES ACTIVE TERMINATION FOR NINE SIGNAL LINES

■ LOW DROPOUT (0.5V) VREGS:2.85V

■ FACTORY TRIMMED TERMINATION 110Ω (±2)

■ POWER DOWN MODE ISOLATES TERMINATION RESISTORS FROM THE BUS

■ FULLY SUPPORTS ACTIVELY NEGATED SCSI SIGNALS

■ COMPATIBLE TO THE DS2107, DS2107A AND DS21S07

■ ONBOARD THERMAL SHUTDOWN CIRCUITRY

■ AVAILABLE IN SO-16L AND TSSOP20

■ SCSI BUS HOT PLUG-COMPATIBLE