Datasheet

SN75976A, SN55976A
9-CHANNEL DIFFERENTIAL TRANSCEIVER
SLLS218B – MAY 1995 – REVISED MAY 1997
19
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
nB–
nB+
nA
nDE/RE
–
+
EN
I/O
620 Ω
†
–
+
EN
I
/O
–
+
SCSI
Connector
SCSI
Connector
SCSI
Connector
I
O
–
+
EN
O
‡
–
+
EN
O
‡
–
+
620 Ω
SCSI
Connector
SCSI
Connector
SCSI
Connector
I
O
I
I
(a) ACTIVE-HIGH BIDIRECTIONAL I/O
WITH SEPARATE ENABLE
(b) ACTIVE-LOW BIDIRECTIONAL I/O
WITH SEPARATE ENABLE
(c) WIRED-OR DRIVER AND ACTIVE-HIGH INPUT
(d) SEPARATE ACTIVE-HIGH INPUT, OUTPUT,
AND ENABLE
(e) SEPARATE ACTIVE-LOW INPUT AND
OUTPUT AND ACTIVE-HIGH ENABLE
(f) WIRED-OR DRIVER AND ACTIVE-LOW INPUT
V
CC
620 Ω
†
V
CC
nA
nDE/RE
nB–
nB+
620 Ω
†
V
CC
nA
nDE/RE
nB–
nB+
620 Ω
†
V
CC
nA
nDE/RE
nB–
nB+
620 Ω
†
V
CC
620 Ω
†
V
CC
nA
nDE/RE
nB–
nB+
620 Ω
†
V
CC
nA
nDE/RE
nB–
nB+
†
When 0 is open drain
‡
Must be open-drain or 3-state output
NOTE A: The BSR, CRE
, A, and DE/RE inputs have internal pullup resistors. CDE0, CDE1, and CDE2 have internal pulldown resistors.
Figure 18. Typical SCSI Transceiver Connections