sp301ct Exar Corporation, sp301ct Datasheet - Page 14

• Manufacturer Part Number: sp301ct
• Description: Rs-232/rs-422 Line Drivers/receivers
• Manufacturer: Exar Corporation

64
shown in these figures, the loopback function
internally connects the driver outputs to the
corresponding receiver inputs, and switches the
output pin to a resistive divider of 10k nominal
impedance from V
puts are left active for signal verification.
During loopback, the receiver inputs are tied to
One-Channel Full Duplex RS-232 &
One-Channel Full Duplex RS-422
RS-422 LINE DRIVER
RS-422 RECEIVER
RS-232 LINE DRIVER
RS-232 RECEIVER
ROB
TIA
ROA
TIB
V
EE
Opposite Drivers
10k
10k
EE
SP301 CONFIGURATIONS IN LOOPBACK MODE
SELECT A = 1
SELECT B = 0
LB = 0
to ground. Receiver out-
(ACTIVE)
TOA
TOA
RIA
RIA
TOB
RIB
10k
10k
2
1
2
1
1
1
10k
10k
V
V
EE
EE
ground via a 5k
mize loopback errors, the receiver inputs must
be limited to 10V swings.
RS-422 LINE DRIVER
RS-422 RECEIVER
RS-422 LINE DRIVER
RS-422 RECEIVER
TIB
ROB
TIA
ROA
Two-Channel Full Duplex RS-422
V
EE
V
EE
SELECT A = 1
SELECT B = 1
LB = 0
10k
10k
pulldown resistor. To mini-
(ACTIVE)
10k
10k
SIGNAL PROCESSING EXCELLENCE
TOA
TOA
TOB
TOB
RIA
RIA
RIB
RIB
2
1
2
1
1
2
1
2
Corporation
10k
10k
10k
10k
V
V
EE
EE