LTC1546 Linear Technology, LTC1546 Datasheet - Page 11

• Manufacturer Part Number: LTC1546
• Description: Software-Selectable Multiprotocol Transceiver with Termination
• Manufacturer: Linear Technology

APPLICATIO S I FOR ATIO
V.10 (RS423) Interface
All V.10 drivers and receivers necessary for the RS449,
EIA530, EIA530-A, V.36 and X.21 protocols are imple-
mented on the LTC1544.
A typical V.10 unbalanced interface is shown in Figure 19.
A V.10 single-ended generator with output A and ground
C is connected to a differential receiver with input A
nected to A, and ground C
to ground C. Usually, no cable termination is required for
V.10 interfaces, but the receiver inputs must be compliant
with the impedance curve shown in Figure 20.
The V.10 receiver configuration in the LTC1544 is shown
in Figure 21. In V.10 mode, switch S3 inside the LTC1544
is turned off. The noninverting input is disconnected
inside the LTC1544 receiver and connected to ground. The
cable termination is then the 30k input impedance to
ground of the LTC1544 V.10 receiver.
V.11 (RS422) Interface
A typical V.11 balanced interface is shown in Figure 22. A
V.11 differential generator with outputs A and B and
ground C is connected to a differential receiver with input
A
connected via the signal return to ground C. The V.11
'
connected to A, input B
U
LTC1546
LTC1544
DCE/DTE
DCE/DTE
'
'
U
(DATA)
(DATA)
connected via the signal return
connected to B, and ground C
M0
M1
M2
M2
M1
M0
11
12
13
14
14
13
12
11
Figure 18: Single Port DCE V.35 Mode Selection in the Cable
W
U
'
con-
'
CONNECTOR
–3.25mA
GENERATOR
–10V
Figure 20. V.10 Receiver Input Impedance
NC
NC
Figure 19. Typical V.10 Interface
C
A
INTERCONNECTING
BALANCED
1546 F18
–3V
CABLE
I
Z
C
A
TERMINATION
'
CABLE
'
3V
CABLE
LTC1546
LOAD
RECEIVER
10V
11
1546 F20
1546 F19
V
3.25mA
Z