UCC5617

具有反向感应、电容最低的 18 线路 3-5V SE 终端，用于 SCSI 至 Ultra SCSI

The provides 18 lines of active termination for a SCSI Small Computers Systems Interface parallel bus. The SCSI standard recommends and Fast-20 Ultra requires active termination at both ends of the cable.

Pin for pin compatible with the UC5609, the UCC5617 is ideal for high performance 5V SCSI systems, Termpwr 4.0-5.25V. During disconnect the supply current is only 50uA typical, which makes the IC attractive for lower powered systems.

The UCC5617 is designed with a low channel capacitance of 2pF, which eliminates effects on signal integrity from disconnected terminators at interim points on the bus.

The power amplifier output stage allows the UCC5617 to source full termination current and sink active negation current when all termination lines are actively negated.

The UCC5617, as with all Unitrode terminators, is completely hot pluggable and appears as high impedance at the terminating channels with TRMPWR = 0V or open.

Internal circuit trimming is utilized, first to trim the 110 impedance, and then most importantly, to trim the output current as close to the maximum SCSI-3 specification as possible, which maximizes noise margin in fast SCSI operation.

This device is offered in low thermal resistance versions of the industry standard 28 pin wide body SOIC.

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Complies with SCSI, SCSI-2, SCSI-3, SPI and FAST-20 Standards

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2pF Channel Capacitance During Disconnect

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50mA Supply Current in Disconnect Mode

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110 Termination

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SCSI Hot Plugging Compliant, 10nA Typical

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+400mA Sinking Current for Active Negation

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–650mA Sourcing Current for Termination

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Trimmed Impedance to 5%

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Thermal Shutdown

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Current Limit