Datasheet

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5 kV rms Signal and Power Isolated

RS-485 Transceiver with ±15 kV ESD

ADM2682E/ADM2687E

Rev. 0

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FEATURES

5 kV rms isolated RS-485/RS-422 transceiver, configurable as

half or full duplex

isoPower integrated isolated dc-to-dc converter

±15 kV ESD protection on RS-485 input/output pins

Complies with ANSI/TIA/EIA-485-A-98 and ISO 8482:1987(E)

Data rate: 16 Mbps (ADM2682E), 500 kbps (ADM2687E)

5 V or 3.3 V operation

Connect up to 256 nodes on one bus

Open- and short-circuit, fail-safe receiver inputs

High common-mode transient immunity: >25 kV/μs

Thermal shutdown protection

Safety and regulatory approvals

UL recognition (pending)

5000 V rms for 1 minute per UL 1577

CSA Component Acceptance Notice #5A (pending)

IEC 60601-1: 400 V rms (basic), 250 V rms (reinforced)

IEC 60950-1: 600 V rms (basic), 380 V rms (reinforced)

VDE Certificates of Conformity (pending)

DIN EN 60747-5-2 (VDE 0884 Part 2): 2003-01

IORM

= 846 V peak

Operating temperature range: −40°C to +85°C

16-lead wide-body SOIC with >8 mm creepage and clearance

APPLICATIONS

Isolated RS-485/RS-422 interfaces

Industrial field networks

Multipoint data transmission systems

FUNCTIONAL BLOCK DIAGRAM

09927-001

ADM2682E/ADM2687E

TxD

RxD

GND

DECODE D

DECODE

ENCODE

OSCILLATOR

RECTIFIER

REGULATOR

ISOOUT

isoPower DC-TO-DC CONVERTER

ISOIN

DIGITAL ISOLATION iCoupler

ENCODE

DECODE

TRANSCEIVER

ISOLATION

BARRIER

Figure 1.

GENERAL DESCRIPTION

The ADM2682E/ADM2687E are fully integrated 5 kV rms

signal and power isolated data transceivers with ±15 kV ESD

protection and are suitable for high speed communication on

multipoint transmission lines. The ADM2682E/ADM2687E

include an integrated 5 kV rms isolated dc-to-dc power supply

that eliminates the need for an external dc-to-dc isolation block.

They are designed for balanced transmission lines and comply

with ANSI/TIA/EIA-485-A-98 and ISO 8482:1987(E).

The devices integrate Analog Devices, Inc., iCoupler® technology to

combine a 3-channel isolator, a three-state differential line driver, a

differential input receiver, and Analog Devices isoPower® dc-to-dc

converter into a single package. The devices are powered by a

single 5 V or 3.3 V supply, realizing a fully integrated signal and

power isolated RS-485 solution.

The ADM2682E/ADM2687E drivers have an active high enable.

An active low receiver enable is also provided, which causes the

receiver output to enter a high impedance state when disabled.

The devices have current limiting and thermal shutdown

features to protect against output short circuits and situations

where bus contention may cause excessive power dissipation.

The parts are fully specified over the industrial temperature

range and are available in a highly integrated, 16-lead, wide-

body SOIC package with >8 mm creepage and clearance.

The ADM2682E/ADM2687E contain isoPower technology that

uses high frequency switching elements to transfer power through

the transformer. Special care must be taken during printed circuit

board (PCB) layout to meet emissions standards. Refer to

AN-0971 Application Note, Recommendations for Control of

Radiated Emissions with isoPower Devices, for details on board

layout considerations.

Summary of content (24 pages)

PAGE 1
5 kV rms Signal and Power Isolated RS-485 Transceiver with ±15 kV ESD ADM2682E/ADM2687E FEATURES FUNCTIONAL BLOCK DIAGRAM VCC VISOOUT isoPower DC-TO-DC CONVERTER OSCILLATOR RECTIFIER VISOIN REGULATOR TRANSCEIVER DIGITAL ISOLATION iCoupler Y TxD ENCODE DECODE D Z DE ENCODE DECODE RxD DECODE ENCODE A R B ADM2682E/ADM2687E RE GND1 ISOLATION BARRIER GND2 Figure 1.
PAGE 2
ADM2682E/ADM2687E TABLE OF CONTENTS Features .............................................................................................. 1 Switching Characteristics .............................................................. 15 Applications....................................................................................... 1 Circuit Description......................................................................... 16 Functional Block Diagram ...................................................
PAGE 3
ADM2682E/ADM2687E SPECIFICATIONS All voltages are relative to their respective ground; 3.0 ≤ VCC ≤ 5.5 V. All minimum/maximum specifications apply over the entire recommended operation range, unless otherwise noted. All typical specifications are at TA = 25°C, VCC = 5 V unless otherwise noted. Table 1.
PAGE 4
ADM2682E/ADM2687E ADM2682E TIMING SPECIFICATIONS TA = −40°C to +85°C. Table 2.
PAGE 5
ADM2682E/ADM2687E REGULATORY INFORMATION Table 5. ADM2682E/ADM2687E Approvals (Pending) Organization UL (Pending) CSA (Pending) VDE (Pending) Approval Type To be recognized under the UL 1577 Component Recognition Program of Underwriters Laboratories, Inc. Single protection, 5000 V rms isolation voltage. In accordance with UL 1577, each ADM2682E/ADM2687E is proof tested by applying an insulation test voltage ≥ 6000 V rms for 1 second. To be approved under CSA Component Acceptance Notice #5A.
PAGE 6
ADM2682E/ADM2687E VDE 0884 INSULATION CHARACTERISTICS (PENDING) This isolator is suitable for basic electrical isolation only within the safety limit data. Maintenance of the safety data must be ensured by means of protective circuits. Table 7.
PAGE 7
ADM2682E/ADM2687E ABSOLUTE MAXIMUM RATINGS TA = 25°C, unless otherwise noted. All voltages are relative to their respective ground. Table 8. Parameter VCC Digital Input Voltage (DE, RE, TxD) Digital Output Voltage (RxD) Driver Output/Receiver Input Voltage Operating Temperature Range Storage Temperature Range ESD (Human Body Model) on A, B, Y, and Z pins ESD (Human Body Model) on Other Pins Thermal Resistance θJA Lead Temperature Soldering (10 sec) Vapor Phase (60 sec) Infrared (15 sec) Rating −0.
PAGE 8
ADM2682E/ADM2687E PIN CONFIGURATION AND FUNCTION DESCRIPTIONS GND1 1 16 GND2 VCC 2 RE 4 DE 5 TxD 6 VCC 7 ADM2682E/ ADM2687E TOP VIEW (Not to Scale) 14 A 13 B 12 Z 11 Y 10 VISOOUT GND1 8 9 GND2 NOTES 1. PIN 10 AND PIN 15 MUST BE CONNECTED EXTERNALLY. 09927-002 RxD 3 15 VISOIN Figure 2. Pin Configuration Table 10. Pin Function Descriptions Pin No.
PAGE 9
ADM2682E/ADM2687E TYPICAL PERFORMANCE CHARACTERISTICS 200 140 120 160 SUPPLY CURRENT, ICC (mA) RL = 54Ω 140 120 RL = 120Ω 100 80 60 NO LOAD 40 RL = 54Ω 100 80 RL = 120Ω 60 40 –15 10 35 60 85 TEMPERATURE (°C) 0 09927-203 0 –40 1 7 10 13 16 DATA RATE (Mbps) Figure 3. ADM2682E Supply Current (ICC) vs. Temperature (Data Rate = 16 Mbps, DE = 3.3 V, VCC = 3.3 V) Figure 6. ADM2682E Supply Current (ICC) vs.
PAGE 10
ADM2682E/ADM2687E 140 600 RL = 54Ω 580 DRIVER PROPAGATION DELAY (ns) SUPPLY CURRENT, ICC (mA) 120 100 RL = 120Ω 80 60 40 NO LOAD 20 560 540 tDPLH 520 tDPHL 500 480 460 440 200 275 350 425 400 –40 09927-209 125 500 DATA RATE (kbps) Figure 9. ADM2687E Supply Current (ICC) vs. Data Rate (TA = 25°C, DE = 3.3 V, VCC = 3.3 V) –15 10 35 TEMPERATURE (°C) 60 85 Figure 12. ADM2687E Differential Driver Propagation Delay vs.
PAGE 11
ADM2682E/ADM2687E 0.32 0 0.30 OUTPUT LOW VOLTAGE (V) –20 –30 –40 –50 0.26 0.24 0.22 0 1 2 3 OUTPUT HIGH VOLTAGE (V) 4 5 09927-111 –60 –70 0.28 0.20 –40 –15 10 35 TEMPERATURE (°C) 60 85 Figure 18. Receiver Output Low Voltage vs. Temperature Figure 15. Receiver Output Current vs. Receiver Output High Voltage 60 B 40 A 1 30 RxD 20 10 3 0 1 2 3 OUTPUT LOW VOLTAGE (V) 4 5 CH1 2.0V CH3 2.0V 09927-112 0 Figure 16. Receiver Output Current vs. Receiver Output Low Voltage CH2 2.
PAGE 12
ADM2682E/ADM2687E 3.44 3.43 ISOLATED SUPPLY VOLTAGE (V) 97 96 tRPHL 95 tRPLH 94 93 3.41 3.40 NO LOAD 3.39 3.38 RL = 120Ω 3.37 RL = 54Ω 3.36 10 35 TEMPERATURE (°C) 60 85 3.34 –40 –15 10 35 60 85 TEMPERATURE (°C) 09927-224 –15 Figure 24. ADM2682E Isolated Supply Voltage vs. Temperature (VCC = 5 V, Data Rate = 16 Mbps) Figure 21. ADM2682E Receiver Propagation Delay vs. Temperature 3.37 100 ISOLATED SUPPLY VOLTAGE (V) 99 98 97 96 tRPHL 95 94 93 92 tRPLH 3.36 3.35 NO LOAD 3.
PAGE 13
ADM2682E/ADM2687E 60 40 40 RL = 120Ω 30 20 NO LOAD 10 0 –40 –15 10 35 60 85 TEMPERATURE (°C) Figure 27. ADM2682E Isolated Supply Current vs. Temperature (VCC = 3.3 V, Data Rate = 16 Mbps) 35 30 RL = 120Ω 25 20 15 10 NO LOAD 5 0 –40 –15 10 35 60 85 TEMPERATURE (°C) Figure 28. ADM2687E Isolated Supply Current vs. Temperature (VCC = 3.3 V, Data Rate = 500 kbps) Rev.
PAGE 14
ADM2682E/ADM2687E TEST CIRCUITS RL 2 VOD2 RL 2 VOC TxD 09927-003 Z VOUT Y Figure 32. Driver Enable/Disable 375Ω A 60Ω Z RxD VTEST B TxD VCC +1.5V CL S1 RL –1.5V CL 09927-005 Z CL Figure 33. Receiver Propagation Delay Figure 30. Driver Voltage Measurement over Common Mode Y VOUT RE RE RxD RL CL VOUT S2 RE IN Figure 31. Driver Propagation Delay Figure 34. Receiver Enable/Disable Rev. 0 | Page 14 of 24 09927-008 375Ω 09927-004 VOD3 TxD S2 CL 50pF Z Figure 29.
PAGE 15
ADM2682E/ADM2687E SWITCHING CHARACTERISTICS VCC VCC/2 VCC/2 0V tDPLH tDPHL VCC Z 1/2VO DE 90% POINT VDIFF tLZ 2.3V Y, Z 90% POINT VDIFF = V(Y) – V(Z) VOL + 0.5V VOL 10% POINT tZH 10% POINT tDF tDR tSKEW = │tDPHL – tDPLH │ tHZ 2.3V VOH VOH – 0.5V Y, Z 09927-009 –VO 0.5VCC 0V tZL Y +VO 0.5VCC 09927-011 VO Figure 37. Driver Enable/Disable Timing Figure 35. Driver Propagation Delay, Rise/Fall Timing VIH RE 0.5VCC 0.5VCC VIL 0V 0V tRPLH tRPHL tZL 1.
PAGE 16
ADM2682E/ADM2687E CIRCUIT DESCRIPTION SIGNAL ISOLATION Table 13. Receiving (see Table 11 for Abbreviations) The ADM2682E/ADM2687E signal isolation of 5 kV rms is implemented on the logic side of the interface. The part achieves signal isolation by having a digital isolation section and a transceiver section (see Figure 1).
PAGE 17
ADM2682E/ADM2687E is assumed to be unpowered or nonfunctional, in which case, the isolator output is forced to a default state by the watchdog timer circuit. This situation should occur in the ADM2682E/ADM2687E devices only during power-up and power-down operations. The limitation on the ADM2682E/ADM2687E magnetic field immunity is set by the condition in which induced voltage in the transformer receiving coil is sufficiently large to either falsely set or reset the decoder.
PAGE 18
ADM2682E/ADM2687E APPLICATIONS INFORMATION PCB LAYOUT The ADM2682E/ADM2687E isolated RS-422/RS-485 transceiver contains an isoPower integrated dc-to-dc converter, requiring no external interface circuitry for the logic interfaces. Power supply bypassing is required at the input and output supply pins (see Figure 41). The power supply section of the ADM2682E/ ADM2687E uses an 180 MHz oscillator frequency to pass power efficiently through its chip-scale transformers.
PAGE 19
ADM2682E/ADM2687E INSULATION LIFETIME waveform that does not conform to Figure 43 or Figure 44 should be treated as a bipolar ac waveform, and its peak voltage should be limited to the 50-year lifetime voltage value listed in Table 9. 0V Accelerated life testing is performed using voltage levels higher than the rated continuous working voltage. Acceleration factors for several operating conditions are determined, allowing calculation of the time to failure at the working voltage of interest.
PAGE 20
ADM2682E/ADM2687E TYPICAL APPLICATIONS Figure 46 and Figure 47 show typical applications of the ADM2682E/ADM2687E in half duplex and full duplex RS-485 network configurations. Up to 256 transceivers can be connected to the RS-485 bus. To minimize reflections, terminate the line at the receiving end in its characteristic impedance and keep stub lengths off the main line as short as possible.
PAGE 21
ADM2682E/ADM2687E MAXIMUM NUMBER OF TRANSCEIVERS ON BUS = 256 ADM2582E/ ADM2587E RxD R A A B B RE TxD RE Z D RxD R RT RT DE ADM2682E/ ADM2687E DE Z Y D Y A B ADM2682E/ ADM2687E R Z Y A D RxD RE B ADM2682E/ ADM2687E DE TxD R Z TxD Y D RxD RE DE TxD 09927-027 NOTES 1. RT IS EQUAL TO THE CHARACTERISTIC IMPEDANCE OF THE CABLE. 2. ISOLATION NOT SHOWN. Figure 46.
PAGE 22
ADM2682E/ADM2687E OUTLINE DIMENSIONS 13.00 (0.5118) 12.60 (0.4961) 16 9 7.60 (0.2992) 7.40 (0.2913) 0.30 (0.0118) 0.10 (0.0039) COPLANARITY 0.10 10.65 (0.4193) 10.00 (0.3937) 8 2.65 (0.1043) 2.35 (0.0925) 1.27 (0.0500) BSC 0.51 (0.0201) 0.31 (0.0122) 0.75 (0.0295) 45° 0.25 (0.0098) 8° 0° SEATING PLANE 0.33 (0.0130) 0.20 (0.0079) 1.27 (0.0500) 0.40 (0.
PAGE 23
ADM2682E/ADM2687E NOTES Rev.