SIP5678 Datasheet, PDF (1/11 Pages) Vishay Siliconix – 15-Line SCSI Bus Terminators

New Product
SiP5678
Vishay Siliconix
15-Line SCSI Bus Terminators
FEATURES
D Auto Selection of S/E or LVD SCSI Termination
D 2.7-V to 5.25-V TERMPWR Range
D Meets SCSI-1, SCSI-2, SPI-2 (ULTRA-2), SPI-3
(ULTRA-160) and SPI-4 (ULTRA-320) Standards
D Integrated SPI-3 Mode Change Delay Filter
D Differential Failsafe Bias
D Thermal Package
D On-Chip Thermal Shutdown Circuit
D Active Negation
D Hot Swap Compatible
D Pin Compatible with UCC5638
D Lead (Pb)-Free SQFP-48 Package
APPLICATIONS
D Disk Array (RAID)
D Storage Area Networks (SAN)
D Network Attached Storage (NAS)
D SCSI Cable
D Server and Workstation
D Industrial Computers
D High-End Personal Computers
DESCRIPTION
The SiP5678 provides active bus termination suitable for all
SCSI bus operational modes from SCSI-1 through SPI-4 (Ultra
SCSI 320). The termination includes impedance matching of
the Ultra SCSI bus to minimize signal reflections from the end
of the bus, as well as required SCSI bus biasing for either S/E
(single ended) or LVD (low voltage differential) operation.
The SiP5678 has fifteen (15) output channels (T1−T15). Each
output channel provides termination for one SCSI data signal,
parity signal or control signal. Two SiP5678 ICs provide
complete termination for a wide SCSI bus.
An integrated mode change delay filter in the SiP5678
eliminates the need for a bulky 4.7-mF low pass filter capacitor
to be compliant with SPI-3 mode change timing requirements.
The SiP5678 senses the operational state of the SCSI bus via
the DIFFSENS bus signal, and automatically switches to S/E
or LVD operation as required. It cannot be used on an HPD
(high power differential) SCSI bus, and goes into high
impedance mode when the voltage on the DIFFSENS line
indicates HPD operation. The SiP5678 also presents high
impedance to the SCSI bus if the DISABLE pin is asserted, or
if TERMPWR is removed from the IC.
The SiP5678 is available in a lead (Pb)-free SQFP-48
package for operation over the temperature range of 0 to
70 _C.
FUNCTIONAL BLOCK DIAGRAM
TERMPWR
3
MODE ³⁴
Comparators
and
Delay Filter
V t 0.5 = S/E
0.7 t V t1.9 = LVD
V u 2.4 = HPD
10 mA
Current Limited
Source/Sink
Regulator
Current Limited
Source/Sink
Regulator
1.3 V
35 _DIFFS
SCSI
Terminator
Impedance
Circuits
2 _T1N
1 _T1P
DISABLE 36
Mode Control And
Enable/Disable
Circuitry
27
4
GND
Document Number: 73100
S-41843—Rev. A, 11-Oct-04
9
28
33
Heat Sink GND Pins
10
REG
48 _T15N
47 _T15P
See Functional Diagrams
(Page 6) for detailed
descriptions of SCSI Terminator
Impedance Circuits in LVD and
S/E modes of operation.
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