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

+5V Multiprotocol, Pin-Selectable
Cable Terminator
PIN
1
2
3
4
5
6
7
8
9
10
11
12, 13
14
15
16
17
18
19
20
21
22
23
24
Pin Description
NAME
M0
V_EE
R1C
R1B
R1A
R2A
R2B
R2C
R3A
R3B
R3C
GND
V_CC
R4B
R4A
R5B
R5A
R6A
R6B
LATCH
DCE/DTE
M2
M1
FUNCTION
Mode-Select Input (Table 1)
Negative Supply Voltage (typically connected to V_EE of MAX13170E). Bypass to GND with a 0.1µF capacitor.
Load 1, Center Tap
Load 1, Node B
Load 1, Node A
Load 2, Node A
Load 2, Node B
Load 2, Center Tap
Load 3, Node A
Load 3, Node B
Load 3, Center Tap
Ground
+5V Supply Voltage. Bypass to GND with a 0.1µF capacitor.
Load 4, Node B
Load 4, Node A
Load 5, Node B
Load 5, Node A
Load 6, Node A
Load 6, Node B
Latch Signal Input. When LATCH is low, the input latches are transparent. When LATCH is high, the data
at the mode-select inputs are latched.
DCE/DTE Mode-Select Input (Table 1)
Mode-Select Input (Table 1)
Mode-Select Input (Table 1)
Detailed Description
The MAX13174E contains six pin-selectable multiproto-
col cable termination networks (Figure 3). Each network
is capable of terminating V.11 (RS-422, RS-530,
RS-530A, RS-449, V.36, and X.21) with a 100Ω differen-
tial load, V.35 with a T-network load, or V.28 (RS-232)
and V.10 (RS-423) with an open-circuit load for use with
transceivers that have on-chip termination. The termina-
tion protocol can be selected by the serial interface
cable wiring or by pin control. The MAX13174E
replaces discrete resistor termination networks and
expensive relays required for multiprotocol termination,
saving space and cost.
The MAX13174E terminator is designed to form a com-
plete +5V cable- or pin-selectable multiprotocol DCE/DTE
interface port when used with the MAX13170E and
MAX13172E transceivers. The MAX13174E terminator
can use the V_EE power generated by the MAX13170E
charge pump, simplifying system design. The
MAX13174E/MAX13170E/MAX13172E are functionally
compatible with the MXL1344A/MXL1543/MXL1544/
MAX3175.
Termination Modes
The termination networks in the MAX13174E can be set
to one of three modes: V.11, V.35, or high impedance.
As shown in Figure 4, in V.11 mode, switch S1 is closed
and switch S2 is open, presenting 104Ω across termi-
nals A and B. In V.35 mode, switches S1 and S2 are
both closed, presenting a T-network with 104Ω differen-
tial impedance and 153Ω common-mode impedance.
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.
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