Rainbow Electronics MAX13175E User Manual
Page 25
MAX13171E/MAX13173E/MAX13175E
Multiprotocol, Pin-Selectable
Data Interface Chipset
______________________________________________________________________________________
25
As shown in Figure 16, in V.11 mode, switch S1 is
closed and switch S2 is open, presenting 104Ω across
terminals A and B. In V.35 mode, switches S1 and S2
are both closed, presenting a T-network with 104Ω dif-
ferential impedance and 153Ω common-mode imped-
ance. In high-impedance mode, switches S1 and S2
are both open, presenting a high impedance across
terminals A and B suitable for V.28 and V.10 modes.
The state of the MAX13175E’s mode-select inputs, M0,
M1, M2, and DCE/DTE determines the mode of each of
the six termination networks. Table 3 shows a cross-ref-
erence of termination mode and select input state for
each of the six termination networks within the
MAX13175E.
R2
52Ω
R3
127Ω
R1
52Ω
S1
CLOSED
A
B
S2
OPEN
(a) V.11
(b) V.35
(c) Z
A
C
B
A
B
MAX13175E
R2
52Ω
R3
127Ω
R1
52Ω
S1
CLOSED
S2
CLOSED
R2
52Ω
R3
127Ω
R1
52Ω
S1
OPEN
S2
OPEN
C
C
MAX13175E
MAX13175E
Figure 16. Termination Modes
PROTOCOL
DCE/
DTE
M2
M1
M0
R1
R2
R3
R4
R5
R6
V.10/RS-423
0
0
0
0
Z
Z
Z
Z
Z
Z
RS-530A
0
0
0
1
Z
Z
Z
V.11
V.11
V.11
RS-530
0
0
1
0
Z
Z
Z
V.11
V.11
V.11
X.21
0
0
1
1
Z
Z
Z
V.11
V.11
V.11
V.35
0
1
0
0
V.35
V.35
Z
V.35
V.35
V.35
RS-449/V.36
0
1
0
1
Z
Z
Z
V.11
V.11
V.11
V.28/RS-232
0
1
1
0
Z
Z
Z
Z
Z
Z
No Cable
0
1
1
1
V.11
V.11
V.11
V.11
V.11
V.11
V.10/RS-423
1
0
0
0
Z
Z
Z
Z
Z
Z
RS-530A
1
0
0
1
Z
Z
Z
Z
V.11
V.11
RS-530
1
0
1
0
Z
Z
Z
Z
V.11
V.11
X.21
1
0
1
1
Z
Z
Z
Z
V.11
V.11
V.35
1
1
0
0
V.35
V.35
V.35
Z
V.35
V.35
RS-449/V.36
1
1
0
1
Z
Z
Z
Z
V.11
V.11
V.28/RS-232
1
1
1
0
Z
Z
Z
Z
Z
Z
No Cable
1
1
1
1
V.11
V.11
V.11
V.11
V.11
V.11
Table 3. MAX13175E Termination Mode Selection