SN75976A Datasheet, PDF (19/35 Pages) Texas Instruments – 9-CHANNEL DIFFERENTIAL TRANSCEIVER

VCC
620 Ω ^†
nA
I/O
EN
nDE/RE
SN75976A, SN55976A
9-CHANNEL DIFFERENTIAL TRANSCEIVER
APPLICATION INFORMATION
SLLS218B – MAY 1995 – REVISED MAY 1997
SCSI
Connector
nB +
+
nB –
–
VCC
620 Ω ^†
nA
I/O
EN
nDE/RE
SCSI
Connector
nB +
–
nB –
+
(a) ACTIVE-HIGH BIDIRECTIONAL I/O
WITH SEPARATE ENABLE
VCC
VCC
620 Ω ^†
620 Ω ^†
nA
I
O
nDE/RE
SCSI
Connector
nB +
+
nB –
–
(b) ACTIVE-LOW BIDIRECTIONAL I/O
WITH SEPARATE ENABLE
VCC
620 Ω ^†
SCSI
Connector
I
O‡
nA
EN
nDE/RE
nB +
+
nB –
–
(c) WIRED-OR DRIVER AND ACTIVE-HIGH INPUT
(d) SEPARATE ACTIVE-HIGH INPUT, OUTPUT,
AND ENABLE
VCC
620 Ω ^†
I
O‡
nA
EN
nDE/RE
SCSI
Connector
nB +
–
nB –
+
VCC
620 Ω ^†
I
O
620 Ω
nA
nDE/RE
SCSI
Connector
nB +
–
nB –
+
(e) SEPARATE ACTIVE-LOW INPUT AND
OUTPUT AND ACTIVE-HIGH ENABLE
(f) WIRED-OR DRIVER AND ACTIVE-LOW INPUT
† _{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
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