Robust 5 kV RMS Isolated RS-485/RS-422 Transceiver
with Level 4 EMC and Full ±42 V Protection
Data Sheet
ADM2795E
FEATURES
APPLICATIONS
5 kV rms isolated RS-485/RS-422 transceiver
Heating, ventilation, and air conditioning (HVAC) networks
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)
Industrial field buses
Building automation
Utility networks
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, DIN V 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 VDD2
1.7 V to 5.5 V operating voltage range on VDD1 logic supply
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 dBꢀV/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
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
ranges, with a 1.7 V to 5.5 V VDD1 power supply range, allowing
interfacing to low voltage logic supplies. The ADM2795E is also
fully TIA/EIA RS-485/RS-422 compliant when operated over a
3 V to 5.5 V VDD2 power supply. The device is fully characterized
over an extended operating temperature range of −40°C to +125°C,
and is available in a 16-lead, wide-body SOIC package.
Glitch free power-up/power-down (hot swap)
FUNCTIONAL BLOCK DIAGRAM
V
V
DD2
DD1
RS-485
TRANSCEIVER
ADM2795E
DIGITAL ISOLATOR
RxD
RE
EMC
A
B
TRANSIENT
PROTECTION
CIRCUIT
DE
TxD
GND
GND
2
1
ISOLATION
BARRIER
Figure 1.
Rev. A
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