MAX13174E Datasheet, PDF (10/13 Pages) Maxim Integrated Products – +5V Multiprotocol, Pin-Selectable Cable Terminator

+5V Multiprotocol, Pin-Selectable
Cable Terminator
GENERATOR
50Ω
125Ω
50Ω
Figure 8. Typical V.35 Interface
BALANCED
INTERCONNECTING
CABLE
A
A′
B
B′
C
C′
LOAD
CABLE
TERMINATION
50Ω
125Ω
50Ω
RECEIVER
A′
A
R1
MAX13174E
52Ω
R5
55kΩ
R8
5kΩ
R6
11kΩ
MAX13170E
RECEIVER
S1
R3
S2 _124Ω
R2
52Ω
B′
S3
+-
1.4V
R7
11kΩ
R4
B
55kΩ
S1
S2
C′
GND
Figure 9. V.35 Termination and Internal Resistance Networks
placed in V.28 mode, all six of the termination networks
are placed in a high-Z mode. In high-Z mode, the
MAX13174E termination networks do not interfere with
the MAX13170E's internal 5kΩ termination.
In Figure 10, the MAX13174E and MAX13170E are
placed in V.28 mode. Switches S1 and S2 are opened
on the MAX13174E to place the network in high-Z
mode. Switch S3 is closed on the MAX13170E to
enable the 5kΩ terminating resistor.
A Complete X.21 Interface
A complete DTE-to-DCE interface operating in X.21
mode is shown in Figure 11. The MAX13174E termi-
nates the V.11 clock and data signals. The MAX13170E
carries the clock and data signals, and the MAX13172E
carries the control signals. The control signals generally
do not require external termination.
ESD Protection
ESD-protection structures are incorporated on all pins
to protect against electrostatic discharges encountered
during handling and assembly. The differential resistors
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