Seagate Barracuda ST11950N, Руководство по эксплуатации продукта

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66 Barracuda 1 and 2 Product Manual, Rev. C
Recommended mating flat cable connector part numbers:
Closed end 3M-3425-7000 Without strain relief,
(for cable ends) no center key
3M-3425-7050 With strain relief, no center key
Dupont-66900-290 With strain relief and center key
Open end 3M-3425-6000 Without strain relief,
(in daisy chain) no center key
3M-3425-6050 With strain relief, no center key
Dupont-66900-250 With strain relief and center key
ST11950W/WD and ST12550W/WD drives
Recommended mating wide cable connector part numbers:
AMP 786096-7, female 68-pin
AMP 786090-7, male 68-pin
11.7.3 Electrical description
ST11950N, ST11950W, ST12550N, and ST12550W drives use single-
ended interface signals. These signals must be terminated with 110 ohm
active terminator circuits at each end of the total cable. Single-ended circuits
use open collector or three-state drivers. ST11950N, ST11950W, ST12550N,
and ST12550W drives can be configured to provide SCSI termination (see
Section 11.7.3.3).
ST11950ND, ST11950WD, ST12550ND and ST12550WD drives use differ-
ential interface signals. Each of these signals must be terminated at each end
of the total cable with 330 ohms to +5V and 330 ohms to ground with 150
ohms between each differential pair. All I/O circuits are open collector, three-
state drivers. Differential I/O drives are shipped without terminators and have
no provisions for adding terminator sockets on the PCB. You must provide
external termination for these drives.
11.7.3.1 Single-ended drivers and receivers
Note. All single-ended terminators must be ANSI SCSI-2 alternative 2
active terminators.
Typical single-ended driver and receiver circuits for the Barracuda 1 and 2
family are shown in Figure 25. Use terminator circuits only when the disc
drive is first or last on the daisy chain. (See Note 1 following Figure 25.)
Transmitter characteristics
Single-ended drives use an ANSI SCSI compatible open-collector single-
ended driver. This driver is capable of sinking a current of 48 mA with a low-
level output voltage of 0.4V.
Receiver characteristics
Single-ended drives use an ANSI SCSI single-ended receiver with hyster-
esis gate or equivalent as a line receiver.