Data Sheet

ADM3061E/ADM3062E/ADM3063E/ADM3064E/

ADM3065E/ADM3066E/ADM3067E/ADM3068E

APPLICATIONS INFORMATION

analog.com

Rev. H | 21 of 25

ISOLATED HIGH SPEED RS-485 NODE

Galvanic isolation, with reinforced insulation and 5 kV rms transi-

ent withstand voltage, can be added to the ADM3065E using

Analog Devices, Inc., iCoupler® and isoPower® technology. The

ADuM6421A provides the required quad channels of 5 kV rms

signal isolation, operating at rates up to 100 Mbps, together with

an integrated dc-to-dc converter. The ADuM6421A combines with

the ADM3065E (shown in Figure 48) with the VISO pin configured

for 3.3 V by connecting the VSEL pin to GNDISO and a 5 V supply

connected to VDDP and VDD1. Operation at 3.3 V ensures the

ADM3065E remains within the load capability of the ADuM6421A.

The dc-to-dc converter in the ADuM6421A isoPower device

provides regulated, isolated power to the ADM3065E. The AD-

uM6421A is designed to meet Class B radiated emissions require-

ments on a 2-layer PCB. See the ADuM6421A data sheet for PCB

layout recommendations.

Galvanic isolation of the ADM3065E at the full data rate, up to

50 Mbps, can be implemented using the ADuM241D quad-channel

digital isolator and the ADuM6028 isolated dc-to-dc converter, as

shown in Figure 49. The ADuM6028 is an 8-pin device that contains

a 300 mW dc-to-dc converter optimized to meet emissions stand-

ards on a 2-layer PCB using two ferrite beads. The ADuM241D

operates at a data rate up to 150 Mbps, and offers the precise

timing required to fully support the ADM3065E at 50 Mbps.

Figure 48. Signal and Power Isolated 25 Mbps RS-485 Solution (Simplified Diagram—All Connections Not Shown)

Figure 49. Signal and Power Isolated 50 Mbps RS-485 Solution (Simplified Diagram—All Connections Not Shown)