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Provides Active Termination for 18
Lines
DESCRIPTION
The UC5607 provides 18 lines of active termination for a SCSI (Small
Computer Systems Interface) parallel bus. The SCSI standard recom-
mends active termination at both ends of the cable segment.
The UC5607 provides a low disconnect feature which will disconnect all
terminating resistors, and will disable the regulator, greatly reducing
standby power. The output channels remain high impedance even without
Termpwr applied.
The UC5607 terminator is specially designed with two disconnect pins for
full SCSI Plug and Play (PnP) applications.
Custom power packages are utilized to allow normal operation at full
power conditions (2 Watts).
Internal circuit trimming is utilized, first to trim the impedance to a 7% tol-
erance, and then most importantly, to trim the output current to a 7% toler-
ance, as close to the max SCSI spec as possible, which maximizes noise
margin in fast SCSI operation.
Other features include thermal shutdown and current limit.
This device is offered in low thermal resistance versions of the industry
standard 28 pin wide body SOIC, and 28 pin PLCC, as well as 24 pin DIP.
BLOCK DIAGRAM
Circuit Design Patented
DISCNCT1
DISCNCT2
Connect Connect Connect
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Disc
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UDG-94124
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