XR3170E-3178E
3
REV. 1.0.0
3.3V HIGH SPEED RS-485/RS-422 TRANSCEIVERS WITH 1/8th UNIT LOAD
PIN DESCRIPTIONS
Pin Assignments
PIN NUMBER
PIN NAME
TYPE
DESCRIPTION
HALF DUPLEX
FULL DUPLEX
1
2
RO
O
Receiver Output. When RE is low and if (A-
B)
≥ -50mV, RO is High. If (A-B) ≤ -200mV,
RO is Low.
2
-
3
RE
I
Receiver Output Enable. When RE is Low,
RO is enabled. When RE is High, RO is
high impedance. RE should be High and
DE should be low to enter shutdown mode.
RE is a hot-swap input.
3
-
4
DE
I
Driver Output Enable. When DE is High,
outputs are enabled. When DE is low, out-
puts are high impedance. DE should be low
and RE should be High to enter shutdown
mode. DE is a hot-swap input.
4
3
5
DI
I
Driver Input. With DE high, a low level on DI
forces Non-Inverting output low and invert-
ing output high. Similarly, a high level on DI
forces Non-Inverting output High and Invert-
ing output Low.
5
4
6, 7
GND
Pwr
Ground.
6
-
A
I/O
Non-Inverting Receiver Input and Non-
Inverting Driver Output.
7
-
B
I/O
Inverting Receiver Input and Inverting
Driver Output.
8
1
14
Vcc
Pwr
+3.3V power supply input. Bypass with
0.1uF capacitor.
-
8
12
A
I
Non-Inverting Receiver Input.
-
7
11
B
I
Inverting Reciever Input.
-
5
9
Y
O
Non-Inverting Driver Output.
-
6
10
Z
O
Inverting Driver Output.
-
1, 8, 13
NC
-
No Connect, not internally connected.
Pin type: I=Input, O=Output.
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