Data Sheet ADM2481
Rev. A | Page 7 of 20
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
NC = NO CONNECT
ADM2481
TOP VIEW
(Not to Scale)
V
DD1
1
V
DD2
16
GND
1
1
2
GND
2
1
15
RxD
3
NC
14
RE
4
B
13
DE
5
A
12
TxD
6
NC
11
GND
1
1
7
GND
2
1
10
GND
1
1
8
GND
2
1
9
1
PIN 2, PIN 7, AND PIN 8 MUST BE CONNECTED TO GND
1
.
PIN 9, PIN 10, AND PIN 15 MUST BE CONNECTED TO GND
2
.
08920-002
Figure 2. Pin Configuration
Table 8. Pin Function Descriptions
Pin No. Mnemonic Description
1 V
DD1
Power Supply (Logic Side).
2, 7, 8 GND
1
Ground (Logic Side).
3 RxD Receiver Output Data. When enabled, if (A − B) ≥ −30 mV, then RxD = high; if (A − B) ≤ −200 mV, then
RxD = low. This is a tristate output when the receiver is disabled, that is, when
RE
is driven high.
4
RE
Receiver Enable Input. This is an active-low input. Driving this input low enables the receiver, and
driving it high disables the receiver.
5 DE Driver Enable Input. Driving the input high enables the driver, and driving it low disables the driver.
6 TxD Transmit Data Input. Data to be transmitted by the driver is applied to this input.
2
11, 14 NC No Connect.
12 A Noninverting Driver Output/Receiver Input. When the driver is disabled, or when V
DD1
or V
DD2
is
powered down, Pin A is put into a high impedance state to avoid overloading the bus.
13 B Inverting Driver Output/Receiver Input. When the driver is disabled, or when V
DD1
or V
DD2
is powered
down, Pin B is put into a high impedance state to avoid overloading the bus.
16 V
DD2
Power Supply (Bus Side).
