Status
All versions are No Longer Available.
Description
The DS2127 Ultra3 LVD/SE SCSI terminator provides
low-voltage differential (LVD)/single-ended (SE) terminations
for 14 SCSI lines. Through the voltage on the
DIFF_CAP pin, the device detects the types of drivers
on the bus. If the device is connected in an LVD-only
bus, the DS2127 provides LVD termination. If any single-
ended devices are connected to the bus, the
DS2127 uses SE termination. If any high-voltage differential
(HVD) devices are connected to the bus, the
DS2127 isolates itself from the SCSI bus. The mode
change has a built-in delay that is determined by an
integrated SPI-3 mode change filter/delay. The terminating
resistors can also be disconnected from the bus
by asserting the ISO pin.
For the LVD termination, the DS2127 provides 14 precisely
trimmed resistors. Each resistor is biased with
two current sources to a fail-safe state. For SE termination,
the DS2127 provides 14 precision 110Ω resistors
and one regulator for active-negation bias.
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Data Sheet
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