adm2481 Analog Devices, Inc., adm2481 Datasheet - Page 13

• Manufacturer Part Number: adm2481
• Description: Half-duplex, Icoupler Isolated Rs-485 Transceiver Adm2481
• Manufacturer: Analog Devices, Inc.

CIRCUIT DESCRIPTION
ELECTRICAL ISOLATION
In the ADM2481, electrical isolation is implemented on the
logic side of the interface. Therefore, the part has two main
sections: a digital isolation section and a transceiver section (see
Figure 26). Driver input and data enable signals, applied to the
TxD and DE pins, respectively, and referenced to logic ground
(GND
transceiver section referenced to isolated ground (GND
Similarly, the receiver output, referenced to isolated ground in
the transceiver section, is coupled across the isolation barrier
to appear at the RxD pin referenced to logic ground (GND
1
), are coupled across an isolation barrier to appear at the
RxD
TxD
DE
RE
GND
V
DD1
DIGITAL ISOLATION
1
Figure 26. Digital Isolation and Transceiver Sections
ENCODE
ENCODE
DECODE
2
).
1
).
ISOLATION
BARRIER
Rev. 0 | Page 13 of 20
DECODE
DECODE
ENCODE
iCoupler Technology
The digital signals are transmitted across the isolation barrier
using iCoupler technology. This technique uses chip-scale
transformer windings to couple the digital signals magnet-
ically from one side of the barrier to the other. Digital inputs
are encoded into waveforms that are capable of exciting the
primary transformer winding. At the secondary winding, the
induced waveforms are then decoded into the binary value that
was originally transmitted.
GND
V
DD2
TRANSCEIVER
2
D
R
A
B
ADM2481