Seagate ST3285N, Product Manual

Page: 32 / 151

2.8.2.1 Single-ended drivers and receivers
The drive uses single-ended drivers and receivers. Schematic repre-
sentations of the removable terminator resistor packs are shown in
Figure 4 on page 21 and Figure 5 on page 21.
•
Transmitter characteristics. The drive uses an ANSI SCSI-compat-
ible, open-collector, single-ended driver. This driver is capable of
sinking a current of 48 mA with a low-level output voltage of 0.4 volts.
•
Receiver characteristics. The drive uses an ANSI SCSI single-
ended receiver with hysteresis gate or equivalent as a line receiver.
The loss in the cable is defined as the difference between the voltages
of the input and output signals, as shown below:
Logic level Driver output (x) Receiver input (x)
Asserted (1)
0.0V
≤
x
≤
0.4V 0.0V
≤
x
≤
0.8V
Negated (0)
2.5V
≤
x
≤
5.25V 2.0V
≤
x
≤
5.25V
2.9 Jumper configurations
The jumper blocks are shown in Figure 6 on page 24 and Figure 7 on
page 25. The jumper applications and part numbers are listed below:
Jumper size Part number Application
2-mm Seagate PN 13211-001
Du Pont PN 89133-001,
Methode PN 8618-202-70,
or equivalent J5 and J8 only
0.1-inch Seagate PN 10562-001
Du Pont PN 86214,
Molex

PN 87092-3013,
or equivalent
All jumper blocks
except J5 and J8
2.9.1 Parity enable option
When a jumper is installed on pins 1 and 2 of the options jumper block,
the parity bit is used. This is the default. When a jumper is not installed
on pins 1 and 2 of the options jumper block, the parity bit is not used.
22 ST3655 Family SCSI Drives Product Manual, Rev. A