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 Industrial field buses Certified Level 4 EMC protection on RS-485 A, B bus pins Building automation IEC 61000-4-5 surge protection (4 kV) Utility networks IEC 61000-4-4 electrical fast transient (EFT) protection (2 kV) GENERAL DESCRIPTION IEC 61000-4-2 electrostatic discharge (ESD) protection The ADM2795E is a 5 kV rms signal isolated RS-485 transceiver 8 kV contact discharge that features up to 42 V of ac/dc peak bus overvoltage fault protec- 15 kV air discharge tion on the RS-485 bus pins. The device integrates Analog Devices, IEC 61000-4-6 conducted radio frequency (RF) immunity Inc., iCoupler technology to combine a 3-channel isolator, RS-485 (10 V/m rms) transceiver, and IEC electromagnetic compatibility (EMC) Certified IEC 61000-4-x immunity across isolation barrier transient protection in a single package. The ADM2795E is a IEC 61000-4-2 ESD, IEC 61000-4-4 EFT, IEC 61000-4-5 surge, RS-485/RS-422 transceiver that integrates IEC 61000-4-5 Level 4 IEC 61000-4-6 conducted RF immunity, IEC 61000-4-3 surge protection, allowing up to 4 kV protection on the RS-485 radiated immunity, IEC 61000-4-8 magnetic immunity bus pins (A and B). The device has IEC 61000-4-4 Level 4 EFT RS-485 A, B pins human body model (HBM) ESD protection: protection up to 2 kV and IEC 61000-4-2 Level 4 ESD protection >30 kV on the bus pins, allowing this device to withstand up to 15 kV on Safety and regulatory approvals (pending) the transceiver interface pins without latching up. This device CSA Component Acceptance Notice 5A, DIN V VDE V 0884-10, UL 1577, CQC11-471543-2012 has an extended common-mode input range of 25 V to improve TIA/EIA RS-485/RS-422 compliant over full supply range data communication reliability in noisy environments. The 3 V to 5.5 V operating voltage range on V ADM2795E is capable of operating over wide power supply DD2 1.7 V to 5.5 V operating voltage range on V logic supply ranges, with a 1.7 V to 5.5 V VDD1 power supply range, allowing DD1 Common-mode input range of 25 V to +25 V interfacing to low voltage logic supplies. The ADM2795E is also High common-mode transient immunity: >75 kV/s fully TIA/EIA RS-485/RS-422 compliant when operated over a Robust noise immunity (tested to the IEC 62132-4 standard) 3 V to 5.5 V V power supply. The device is fully characterized DD2 Passes EN55022 Class B radiated emissions by 6 dBV/m margin over an extended operating temperature range of 40C to +125C, Receiver short-circuit, open-circuit, and floating input fail-safe and is available in a 16-lead, wide-body SOIC package. Supports 256 bus nodes (96 k receiver input impedance) 40C to +125C temperature option Glitch free power-up/power-down (hot swap) FUNCTIONAL BLOCK DIAGRAM V V DD1 DD2 RS-485 ADM2795E DIGITAL ISOLATOR TRANSCEIVER RxD RE EMC A TRANSIENT DE PROTECTION CIRCUIT B TxD GND GND 1 2 ISOLATION BARRIER Figure 1. Rev. B Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 2016-2020 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Technical Support www.analog.com Trademarks and registered trademarks are the property of their respective owners. 14129-001ADM2795E Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Overvoltage Fault Protection .................................................... 16 Applications ....................................................................................... 1 42 V Miswire Protection ......................................................... 16 General Description ......................................................................... 1 RS-485 Network Biasing and Termination ............................. 16 Functional Block Diagram .............................................................. 1 IEC ESD, EFT, and Surge Protection ....................................... 17 Revision History ............................................................................... 2 IEC Conducted, Radiated, and Magnetic Immunity ............. 21 Specificat ions ..................................................................................... 3 Applications Information .............................................................. 23 Timing Specifications .................................................................. 4 Radiated Emissions and PCB Layout ...................................... 23 Insulation and Safety-Related Specifications ............................ 5 Noise Immunity .......................................................................... 23 Package Characteristics ............................................................... 5 Fully RS-485 Compliant over an Extended 25 V Common- Mode Voltage Range .................................................................. 23 Regulatory Information ............................................................... 5 1.7 V to 5.5 V VDD1 Logic Supply .............................................. 23 DIN V VDE V 0884-10 (VDE V 0884-10) Insulation Characteristics .............................................................................. 6 Truth Tables................................................................................. 24 Absolute Maximum Ratings ............................................................ 7 Receiver Fail-Safe ....................................................................... 24 Thermal Resistance ...................................................................... 7 RS-485 Data Rate and Bus Capacitance .................................. 24 ESD Caution .................................................................................. 7 Insulation Wear Out .................................................................. 24 Pin Configuration and Function Descriptions ............................. 8 Hot Swap Capability................................................................... 25 Typical Performance Characteristics ............................................. 9 Robust Half-Duplex RS-485 Network ..................................... 25 Test Circuits ..................................................................................... 13 EMC Compliant and Fault Protected Signal and Power Isolated RS-485 Node ................................................................ 27 Switching Characteristics .......................................................... 14 Outline Dimensions ....................................................................... 28 Theory of Operation ...................................................................... 15 Ordering Guide .......................................................................... 28 RS-485 with Robustness ............................................................ 15 Integrated and Certified IEC EMC Solution .......................... 15 REVISION HISTORY 1/2020Rev. A to Rev. B Added EMC Compliant and Fault Protected Signal and Power Isolated RS485 Node Section, Table 2 Renumbered Sequentially, and Figure 53 Renumbered Sequentially ............ 27 3/2017Rev. 0 to Rev. A Changes to Table 5 ............................................................................ 5 Changes to DIN V VDE V 0884-10 (VDE V 0884-10) Insulation Characteristics Section .................................................. 6 10/2016Revision 0: Initial Version Rev. B Page 2 of 28