sip5638 Vishay, sip5638 Datasheet - Page 10

• Manufacturer Part Number: sip5638
• Description: Sip5638 - 15-line Scsi Bus Terminators
• Manufacturer: Vishay

SiP5638
Vishay Siliconix
DETAILED OPERATION
The SiP5638 is a multimode active terminator IC, which
detects the operating mode of the SCSI bus, and switches to
the appropriate termination configuration accordingly.
Two SiP5638 terminators are required at each end of a wide
SCSI bus to terminate 27 lines (18 data, 9 control). In LVD
mode the SiP5638 provides 105-W differential impedance and
112-mV differential bias between each TN/TP pair of
terminator lines. In S/E mode the SiP5638 provides 108-W
impedance and 2.7-V pull-up on each TxN pin, and low
impedance to ground on each TxP pin. In HPD mode the
SiP5638 disconnects from the bus and presents high
impedance to all TN/TP lines.
Each SiP5638 IC has a 1.3-V DIFFSENS regulator output that
can be used to drive the DIFFSENS line of a SCSI bus. The
DIFFSENS regulator attempts to drive the DIFFSENS control
signal to 1.3 V, but is current limited so that S/E or HPD devices
Vishay Siliconix maintains worldwide manufacturing capability. Products may be manufactured at one of several qualified locations. Reliability data for Silicon Technology and
Package Reliability represent a composite of all qualified locations.
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For related documents such as package/tape drawings, part marking, and reliability data, see
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on the SCSI bus can override the DIFFSENS regulator and put
the bus into S/E or HPD mode of operation.
The MODE pin senses the operational state of the SCSI bus
by detecting the voltage on the DIFFSENS control line through
an
recommended component values for the filter to meet SPI-3
mode change requirements.
The DISABLE pin is used to connect/disconnect the SiP5638.
If it is pulled to GROUND the SiP5638 is in connect mode, and
operates as a terminator. If it is pulled to TRMPWR or left open
the device is in disconnect mode and presents high
impedance to the SCSI bus.
DIFFSENS regulator is disabled.
The SiP5638 operates within SCSI specifications with the
TERMPWR voltage between 2.7 V and 5.25 V, which enables
it to operate in both 5-V and 3.3-V systems. The 2.7-V lower
limit guarantees correct performance in a 3.3-V system.
external
R/C
lowpass
filter.
In disconnect mode the
S-41843—Rev.A, 11-Oct-04
Document Number: 73098
50 kW/4.7 mF
are