Datasheet

ADM2485
Rev. A | Page 9 of 20
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
D1 1
D2 2
G
ND
1
3
V
DD1
4
V
DD2
16
GND
2
15
GND
2
14
B
13
RxD 5 A 12
RE 6 GND
2
11
RTS
7
DE OUT
10
TxD 8 GND
2
9
ADM2485
TOP VIEW
(Not to Scale)
06021-002
Figure 6. Pin Configuration
Table 8. Pin Function Description
Pin No. Mnemonic Function
1 D1 Transformer Driver Terminal 1.
2 D2 Transformer Driver Terminal 2.
3 GND
1
Ground, Logic Side.
4 V
DD1
Power Supply, Logic Side (3.3 V or 5 V). Decoupling capacitor to GND
1
required; capacitor value should be
between 0.01 μF and 0.1 μF.
5 RxD
Receiver Output Data. This output is high when (A − B) > 200 mV and low when (A − B) < −200 mV. The
output is tristated when the receiver is disabled, that is, when
RE is driven high.
6
RE Receiver Enable Input. This is an active-low input. Driving this input low enables the receiver; driving it
high disables the receiver.
7 RTS Driver Enable Input. Driving this input high enables the driver; driving it low disables the driver.
8 TxD Driver Input. Data to be transmitted by the driver is applied to this input.
9, 11, 14, 15 GND
2
Ground, Bus Side.
10 DE OUT Driver Enable Status Output.
12 A
Noninverting Driver Output/Receiver Input. When the driver is disabled or V
DD1
or V
DD2
is powered down,
Pin A is put in a high impedance state to avoid overloading the bus.
13 B
Inverting Driver Output/Receiver Input. When the driver is disabled or V
DD1
or V
DD2
is powered down,
Pin B is put in a high impedance state to avoid overloading the bus.
16 V
DD2
Power Supply, Bus Side (Isolated 5 V Supply). Decoupling capacitor to GND
2
required; capacitor value
should be between 0.01 μF and 0.1 μF.