Robust 5 kV RMS Isolated RS-485/RS-422 Transceiver

with Level 4 EMC and Full ±42 V Protection

Data Sheet

ADM2795E

Rev. 0

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FEATURES

5 kV rms isolated RS-485/RS-422 transceiver

±42 V ac/dc peak fault protection on RS-485 bus pins

Certified Level 4 EMC protection on RS-485 A, B bus pins

IEC 61000-4-5 surge protection (±4 kV)

IEC 61000-4-4 electrical fast transient (EFT) protection (±2 kV)

IEC 61000-4-2 electrostatic discharge (ESD) protection

±8 kV contact discharge

±15 kV air discharge

IEC 61000-4-6 conducted radio frequency (RF) immunity

(10 V/m rms)

Certified IEC 61000-4-x immunity across isolation barrier

IEC 61000-4-2 ESD, IEC 61000-4-4 EFT, IEC 61000-4-5 surge,

IEC 61000-4-6 conducted RF immunity, IEC 61000-4-3

radiated immunity, IEC 61000-4-8 magnetic immunity

RS-485 A, B pins human body model (HBM) ESD protection:

>±30 kV

Safety and regulatory approvals (pending)

CSA Component Acceptance Notice 5A, DINV VDE V 0884-10,

UL 1577, CQC11-471543-2012

TIA/EIA RS-485/RS-422 compliant over full supply range

3 V to 5.5 V operating voltage range on V

DD2

1.7 V to 5.5 V operating voltage range on V

Common-mode input range of −25 V to +25 V

High common-mode transient immunity: >75 kV/μs

Robust noise immunity (tested to the IEC 62132-4 standard)

Passes EN55022 Class B radiated emissions by 6 dBµV/m margin

Receiver short-circuit, open-circuit, and floating input fail-safe

Supports 256 bus nodes (96 kΩ receiver input impedance)

−40°C to +125°C temperature option

Glitch free power-up/power-down (hot swap)

APPLICATIONS

Heating, ventilation, and air conditioning (HVAC) networks

Industrial field buses

Building automation

Utility networks

GENERAL DESCRIPTION

The ADM2795E is a 5 kV rms signal isolated RS-485 transceiver

that features up to ±42 V of ac/dc peak bus overvoltage fault protec-

tion on the RS-485 bus pins. The device integrates Analog Devices,

Inc., iCoupler® technology to combine a 3-channel isolator, RS-485

transceiver, and IEC electromagnetic compatibility (EMC)

transient protection in a single package. The ADM2795E is a

RS-485/RS-422 transceiver that integrates IEC 61000-4-5 Level 4

surge protection, allowing up to ±4 kV protection on the RS-485

bus pins (A and B). The device has IEC 61000-4-4 Level 4 EFT

protection up to ±2 kV and IEC 61000-4-2 Level 4 ESD protection

on the bus pins, allowing this device to withstand up to ±15 kV on

the transceiver interface pins without latching up. This device

has an extended common-mode input range of ±25 V to improve

data communication reliability in noisy environments. The

ADM2795E is capable of operating over wide power supply

interfacing to low voltage logic supplies. The ADM2795E is also

fully TIA/EIA RS-485/RS-422 compliant when operated over a

over an extended operating temperature range of −40°C to +125°C,

and is available in a 16-lead, wide-body SOIC package.

FUNCTIONAL BLOCK DIAGRAM

Figure 1.

RxD

RE

DE

RS-485

TRANSCEIVER

TxD

A

B

ADM2795E

EMC

TRANSIENT

PROTECTION

CIRCUIT

DIGITAL ISOLATOR

ISOLATION

BARRIER