DS21T07

DS21T07 SCSI Terminator www.dalsemi.com 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) PIN ASSIGNMENT TERMPWR1 R1 R2 R3 R4 R5 VREF1 GND 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 PD VREF2 NC R9 R8 R7 R6 TERMPWR2 DS21T07S 16-pin SOIC (300-mil) TERMPWR1 HS-GND R1 R2 R3 R4 R5 HS-GND VREF1 GND 1 2 3 4 5 6 7 8 9 10 20 19 18 17 16 15 14 13 12 11 PD VREF2 HS-GND NC R9 R8 R7 R6 HS-GND TERMPWR2 DS21T07E 20-pin TSSOP (173-mil) ACTUAL FOOTPRINT SIZE 0.41” 0.26” 0.41” 0.27” DS21T07S DS21T07E 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 r...