DS21T09
BUS GROUND SENSING
If internal and external SCSI devices are connected to the SCSI bus, the DS21T09 will disconnect from
the SCSI bus according to the circuit in Figure 3. To utilize this automatic disconnect method of bus
sensing, configure the DS21T09 as shown in Figure 4. The
PDI
(Power Down Internal) pin should be
connected to pin 22 of the internal SCSI connector, and the
PDE
(Power Down External) connected to
pin 36 of the external SCSI connector.
BUS GROUND SENSING CIRCUIT
Figure 3
BUS GROUND DETECT CONFIGURATION
Figure 4
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