ADM2795EBRWZ_技术文档

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 V_DD2

1.7 V to 5.5 V operating voltage range on V_DD1logic 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 V_DD1power 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 V_DD2power 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

DD2

DD1

RS-485

TRANSCEIVER

ADM2795E

DIGITAL ISOLATOR

RxD

RE

EMC

A

B

TRANSIENT

PROTECTION

CIRCUIT

DE

TxD

GND

2

1

ISOLATION

BARRIER

Figure 1.

Rev. A

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Tel: 781.329.4700

Technical Support

www.analog.com

ADM2795E* PRODUCT PAGE QUICK LINKS

Last Content Update: 07/15/2017

COMPARABLE PARTS

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REFERENCE MATERIALS

Press

• Analog Devices’ RS-485 Transceivers First to Meet

Stringent IEC Surge Standards

EVALUATION KITS

• ADM2795E Evaluation Board

DESIGN RESOURCES

• ADM2795E Material Declaration

• PCN-PDN Information

DOCUMENTATION

Application Notes

• Quality And Reliability

• AN-1398: System Level EMC Solution for Isolated RS-485

Communication Interfaces in Harsh Industrial

Environments Using the ADM2795E

• Symbols and Footprints

Data Sheet

DISCUSSIONS

View all ADM2795E EngineerZone Discussions.

• ADM2795E-EP: Enhanced Data Sheet

• ADM2795E: Robust 5 kV RMS Isolated RS-485/RS-422

Transceiver with Level 4 EMC and Full ±42 V Protection

Data Sheet

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TOOLS AND SIMULATIONS

• ADM2795E IBIS Model

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ADM2795E

Data Sheet

TABLE OF CONTENTS

Features .............................................................................................. 1

Integrated and Certified IEC EMC Solution.......................... 15

Overvoltage Fault Protection.................................................... 16

42 V Miswire Protection......................................................... 16

RS-485 Network Biasing and Termination............................. 16

IEC ESD, EFT, and Surge Protection....................................... 17

IEC Conducted, Radiated, and Magnetic Immunity............. 21

Applications Information.............................................................. 23

Radiated Emissions and PCB Layout ...................................... 23

Noise Immunity.......................................................................... 23

Applications....................................................................................... 1

General Description......................................................................... 1

Functional Block Diagram .............................................................. 1

Revision History ............................................................................... 2

Specifications..................................................................................... 3

Timing Specifications .................................................................. 4

Insulation and Safety-Related Specifications............................ 5

Package Characteristics ............................................................... 5

Regulatory Information............................................................... 5

Fully RS-485 Compliant over an Extended 25 V Common-

Mode voltage Range................................................................... 23

DIN V VDE V 0884-10 (VDE V 0884-10) Insulation

Characteristics .............................................................................. 6

1.7 V to 5.5 V V_DD1Logic Supply.............................................. 23

Truth Tables................................................................................. 24

Receiver Fail-Safe ....................................................................... 24

RS-485 Data Rate and Bus Capacitance.................................. 24

Insulation Wear Out .................................................................. 24

Hot Swap Capability................................................................... 25

Robust Half-Duplex RS-485 Network..................................... 25

Outline Dimensions....................................................................... 27

Ordering Guide .......................................................................... 27

Absolute Maximum Ratings............................................................ 7

Thermal Resistance ...................................................................... 7

ESD Caution.................................................................................. 7

Pin Configuration and Function Descriptions............................. 8

Typical Performance Characteristics ............................................. 9

Test Circuits..................................................................................... 13

Switching Characteristics .......................................................... 14

Theory of Operation ...................................................................... 15

RS-485 with Robustness ............................................................ 15

10/2016—Revision 0: Initial Version

REVISION HISTORY

3/2017—Rev. 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

Rev. A | Page 2 of 27

Data Sheet

ADM2795E

SPECIFICATIONS

1.7 V ≤ V_DD1≤ 5.5 V, 3 V ≤ V_DD2≤ 5.5 V, T_A= −40°C to +125°C. All min/max specifications apply over the entire recommended operation

range, unless otherwise noted. All typical specifications at T_A= 25°C, V_DD1= V_DD2= 5.0 V, unless otherwise noted.

Table 1.

Parameter

Symbol Min

Typ

Max

Unit

Test Conditions/Comments

SUPPLY CURRENT

Power Supply Current

Logic Side

I_DD1

I_DD2

10

mA

Unloaded output, DE = V_DD1, RE = 0 V

TxD/RxD Data Rate = 2.5 Mbps

Bus Side

TxD/RxD Data Rate = 2.5 Mbps

12

90

130

DE = V_DD1, RE = 0 V, V_DD2= 5.5 V,

R = 27 Ω, see Figure 27

94

46

mA

DE = V_DD1, RE = 0 V, V_DD2= 5.5 V,

R = 27 Ω, see Figure 27

DE = V_DD1, RE = 0 V, V_DD2= 3.0 V,

R = 27 Ω, see Figure 27

Supply Current in Shutdown Mode

DRIVER

I_SHDN

10

DE = 0 V, RE = V_DD1

Differential Outputs

Differential Output Voltage

|V_OD

|

1.5

2.1

1.5

2.1

5.0

0.2

V

V_DD2≥ 3.0 V, R = 27 Ω or 50 Ω,

see Figure 27

V_DD2≥ 4.5 V, R = 27 Ω or 50 Ω,

see Figure 27

V_DD2≥ 3.0 V, V_CM= −25 V to +25 V, see

Figure 28

V_DD2≥ 4.5 V, V_CM= −25 V to +25 V, see

Figure 28

|V_OD3

|

Change in Differential Output Voltage

for Complementary Output States

∆|V_OD

|

R = 27 Ω or 50 Ω, see Figure 27

Common-Mode Output Voltage

V_OC

∆|_VOC|

3.0

0.2

V

R = 27 Ω or 50 Ω, see Figure 27

Change in Common-Mode Output

Voltage for Complementary Output

States

Short-Circuit Output Current

V_OUT= Low

V_OUT= High

I_OSL

I_OSH

−250

+250

mA

−42 V ≤ V_SC≤ +42 V¹

Logic Inputs (DE, RE, TxD)

Input Threshold Low

Input Threshold High

Input Current

V_IL

V_IH

I_TxD

0.33 × V_DD1

+1

V

μA

1.7 V ≤ V_DD1≤ 5.5 V

0 V ≤ V_IN≤ V_DD1

0.7 V_DD1

RECEIVER

Differential Inputs

Differential Input Threshold Voltage

Input Voltage Hysteresis

Input Current (A, B)

V_TH

V_HYS

I_I

−200

−125 −30

30

mV

mA

pF

−25 V ≤ V_CM≤ +25 V

DE = 0 V, V_DD2= 0 V/5 V, V_IN

T_A= 25°C, see Figure 17

−1.0

+1.0

=

25 V

42 V

Input Capacitance (A, B)

Line Input Resistance

C_AB

R_IN

150

96

kΩ

−25 V ≤ V_CM≤ +25 V, up to 256 nodes

supported

Rev. A | Page 3 of 27

ADM2795E

Data Sheet

Parameter

Symbol Min

Typ

Max

Unit

Test Conditions/Comments

Logic Outputs

Output Voltage Low

Output Voltage High

Short-Circuit Current

V_OLRxD

V_OHRxD

0.2

V

mA

μA

I_ORxD= 3.0 mA, V_A− V_B= −0.2 V

I_ORxD= −3.0 mA, V_A− V_B= 0.2 V

V_OUT= GND or V_DD1, RE = 0 V

RE = V_DD1, RxD = 0 V or V_DD1

V_DD1− 0.2

100

±2

Three-State Output Leakage Current

I_OZR

COMMON-MODE TRANSIENT IMMUNITY²

75

125

kV/μs V_CM≥1 kV, transient magnitude ≥800 V

¹V_SCis the short-circuit voltage at the RS-485 A or B bus pin.

²Common-mode transient immunity is the maximum common-mode voltage slew rate that can be sustained while maintaining specification-compliant operation. V_CM

is the common-mode potential difference between the logic and bus sides. The transient magnitude is the range over which the common mode is slewed. The

common-mode voltage slew rates apply to both rising and falling common-mode voltage edges.

TIMING SPECIFICATIONS

V_DD1= 1.7 V to 5.5 V, V_DD2= 3.0 V to 5.5 V, T_A= T_MINto T_MAX(−40°C to +125°C), unless otherwise noted.

Table 2.

Parameter

DRIVER¹

Min

Typ

Max

Unit

Test Conditions/Comments

Maximum Data Rate

Propagation Delay, t_DPLH, t_DPHL

Differential Skew, t_SKEW

Rise/Fall Times, t_R, t_F

Enable Time, t_ZH, t_ZL

Disable Time, t_HZ, t_LZ

RECEIVER²

2.5

Mbps

ns

30

10

40

500

50

130

2500

R_LDIFF= 54 Ω, C_L1= C_L2= 100 pF, see Figure 29 and Figure 33

R_L= 110 Ω, C_L= 50 pF, see Figure 30 and Figure 35

ns

R_L= 110 Ω, C_L= 50 pF, see Figure 30 and Figure 35

Propagation Delay, t_PLH, t_PHL

120

140

4

10

200

220

40

50

ns

C_L= 15 pF, see Figure 31 and Figure 34, 10, V_ID≥ ±1.5 V

C_L= 15 pF, see Figure 31 and Figure 34, V_ID≥ ±±00 mV

C_L= 15 pF, see Figure 31 and Figure 34, V_ID≥ ±1.5 V

R_L= 1 kΩ, C_L= 15 pF, see Figure 32 and Figure 3±

C_L= 15 pF, see Figure 31 and Figure 34, V_ID≥ ±1.5 V

Skew, t_SKEW

Enable Time

Disable Time

RxD Pulse Width Distortion

40

¹See Figure 29 for the definition of R_LDIFF

.

²Receiver propagation delay, skew, and pulse width distortion specifications are tested with a receiver differential input voltage (V_ID) of ≥±±00 mV or ≥±1.5 V, as noted.

Rev. A | Page 4 of 27

Data Sheet

ADM2795E

INSULATION AND SAFETY-RELATED SPECIFICATIONS

For additional information, see www.analog.com/icouplersafety.

Table 3.

Parameter

Symbol

Value

5000

7.8

Unit

Conditions

Rated Dielectric Insulation Voltage

Minimum External Air Gap (Clearance)

V rms

mm min

1 minute duration

Measured from input terminals to output terminals,

shortest distance through air

Measured from input terminals to output terminals,

shortest distance along body

Measured from input terminals to output terminals,

shortest distance through air, line of sight, in the PCB

mounting plane

L(I01)

L(I02)

L(PCB)

Minimum External Tracking (Creepage)

7.8

8.3

mm min

Minimum Clearance in the Plane of the Printed

Circuit Board (PCB Clearance)

Minimum Internal Gap (Internal Clearance)

Tracking Resistance (Comparative Tracking Index)

Material Group

25.5

>400

II

μm min

V

Minimum distance through insulation

DIN IEC 112/VDE 0303 Part 1

Material Group (DIN VDE 0110, 1/89)

CTI

PACKAGE CHARACTERISTICS

Table 4.

Parameter

Symbol Min Typ Max Unit Test Conditions/Comments

Resistance (Input to Output)¹

Capacitance (Input to Output)¹

Input Capacitance²

R_I-O

C_I-O

C_I

10¹³

Ω

2.2

4.0

150

59.7

pF

f = 1 MHz

T_A= 25°C, see Figure 17

Input Capacitance, A and B Pins

IC Junction to Ambient Thermal Resistance θ_JA

C_AB

°C/W Thermocouple located at center of package underside

¹The device is considered a 2-terminal device: Pin 1 through Pin 8 are shorted together, and Pin 9 through Pin 16 are shorted together.

²Input capacitance is from any digital input pin to ground.

REGULATORY INFORMATION

See Table 8 and the Insulation Wear Out section for details regarding recommended maximum working voltages for specific cross

isolation waveforms and insulation levels. The ADM2795E is approved or pending approval by the organizations listed in Table 5.

Table 5. ADM2795E Approvals

UL

CSA

VDE

CQC (Pending)

Recognized Under UL 1577

Component Recognition

Program¹

Approved under CSA Component

Acceptance Notice 5A

Certified according to DIN V VDE V 0884-

10 (VDE V 0884-10):2006-12²

Certified by

CQC11-471543-2012,

GB4943.1-2011

Single Protection, 5000 V rms

Isolation Voltage

CSA 60950-1-07+A1+A2 and IEC 60950-1

second edition +A1+A2:

Reinforced insulation, V_IORM= 849 V peak, Basic insulation at

V_IOSM= 8000 V peak

780 V rms (1103 V peak)

Basic insulation at 780 V rms

(1103 V peak)

Reinforced insulation at

389 V rms (552 V peak)

Reinforced insulation at 390 V rms

(552 V peak)

IEC 60601-1 Edition 3.1: 1 means of

patient protection (MOPP), 400 V rms

(566 V peak)

2 MOPP, 237 V rms (335 V peak)

CSA 61010-1-12+A1 and IEC 61010-1 third

edition:

Basic insulation at 600 V rms mains

(Overvoltage Category III), 780 V

secondary (1103 V peak)

File E214100

File 205078

File 2471900-4880-0001/231230

File (pending)

¹In accordance with UL 1577, each ADM2795E is proof tested by applying an insulation test voltage ≥ 6000 V rms for 1 sec.

²In accordance with DIN V VDE V 0884-10, each ADM2795E is proof tested by applying an insulation test voltage ≥1592 V peak for 1 sec.

Rev. A | Page 5 of 27

ADM2795E

Data Sheet

DIN V VDE V 0884-10 (VDE V 0884-10) INSULATION CHARACTERISTICS

This isolator is suitable for reinforced electrical isolation only within the safety limit data. Maintenance of the safety data must be ensured

by means of protective circuits.

An asterisk (*) on a package denotes VDE 0884 approval for a 849 V peak working voltage.

Table 6.

Description

Test Conditions/Comments

Symbol Characteristic Unit

Installation Classification per DIN VDE 0110 for

Rated Mains Voltage

≤150 V rms

≤300 V rms

≤400 V rms

Climatic Classification

Pollution Degree (DIN VDE 0110, see Table 3)

Maximum Working Insulation Voltage

Input to Output Test Voltage, Method b1

I to IV

I to III

40/125/21

2

V_IORM

V_PR

849

1592

V peak

V_IORM× 1.875 = V_PR, 100% production tested, t_m=

1 sec, partial discharge < 5 pC

Input to Output Test Voltage, Method a

After Environmental Tests, Subgroup 1

After Input and/or Safety Test,

Subgroup 2/Subgroup 3

V_PR

V_IORM× 1.5 = V_PR, t_m= 60 sec, partial discharge < 5 pC

V_IORM× 1.2 = V_PR, t_m= 60 sec, partial discharge < 5 pC

1274

1019

V peak

Highest Allowable Overvoltage

Reinforced Surge Isolation Voltage

Safety Limiting Values

Transient overvoltage, t_TR= 10 sec

V_PEAK= 12.8 kV, 1.2 μs rise time, 50 μs, 50% fall time

Maximum value allowed in the event of a failure,

see Figure 2

V_IOTM

V_IOSM

T_S

7000

8000

150

V peak

°C

Total Power Dissipation at T_A= 25°C

Insulation Resistance at T_S

P_S

R_S

1.80

>10⁹

W

Ω

V_IO= 500 V

2.0

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0

50

100

150

AMBIENT TEMPERATURE (°C)

Figure 2. Thermal Derating Curve for RW-16 Wide Body [SOIC_W] Package,

Dependence of Safety Limiting Values with Ambient Temperature per

DIN V VDE V 0884-10

Rev. A | Page 6 of 27

Data Sheet

ADM2795E

ABSOLUTE MAXIMUM RATINGS

T_A= 25°C, unless otherwise noted.

Table 8. Maximum Continuous Working Voltage¹

Parameter

Max Unit

Reference Standard²

Table 7.

AC Voltage

Parameter

Rating

Bipolar Waveform

Basic Insulation

V_DD1

−0.5 V to +7 V

849

768

V peak

50-year minimum

insulation lifetime

V_DD2

−0.5 V to +7 V

Digital Input/Output Voltage (DE, RE,

TxD, RxD)

−0.3 V to V_DD1+ 0.3 V

Reinforced

Insulation

Lifetime limited by

package creepage

maximum approved

working voltage per

IEC 60950-1

Driver Output/Receiver Input Voltage

Operating Temperature Range

Storage Temperature Range

Maximum Junction Temperature

Continuous Total Power Dissipation

Lead Temperature

48 V

−40°C to +125°C

−65°C to +150°C

150°C

Unipolar Waveform

Basic Insulation

1698 V peak

885 V peak

50-year minimum

insulation lifetime

405 mW

Reinforced

Insulation

Lifetime limited by

package creepage

maximum approved

working voltage per

IEC 60950-1

Soldering (10 sec)

Vapor Phase (60 sec)

Infrared (15 sec)

300°C

215°C

220°C

ESD (A, B Pins Tested to GND₂)

IEC 61000-4-2 Contact Discharge

IEC 62000-4-2 Air Discharge

EFT (A, B Pins Tested to GND₂)

IEC 61000-4-4 Level 4 EFT Protection

Surge (A, B Pins Tested to GND₂)

8 kV

15 kV

DC Voltage

Basic Insulation

1092 V peak

Lifetime limited by

package creepage

maximum approved

working voltage per

IEC 60950-1

2 kV

4 kV

IEC 61000-4-5 Level 4 Surge

Protection

Reinforced

Insulation

543

V peak

Lifetime limited by

package creepage

maximum approved

working voltage per

IEC 60950-1

EMC Performance from A, B Bus Pins

Across the Isolation Barrier to GND₁

ESD

IEC 61000-4-2 Contact Discharge

IEC 61000-4-2 Air Discharge

EFT

IEC 61000-4-4

Surge

9 kV

8 kV

¹The maximum continuous working voltage refers to the continuous voltage

magnitude imposed across the isolation barrier. See the Insulation Wear Out

section for more details.

²Insulation lifetime for the specified test condition is greater than 50 years.

2 kV

THERMAL RESISTANCE

IEC 61000-4-5

HBM ESD Protection (A, B Pins Tested to

GND₂)

4 kV

> 30 kV

Thermal performance is directly linked to PCB design and

operating environment. Careful attention to PCB thermal

design is required.

HBM ESD Protection (All Pins)

6 kV

θ_JAis the natural convection junction to ambient thermal resistance

measured in a one cubic foot sealed enclosure. θ_JCis the junction to

case thermal resistance.

Field Induced Charged Device Model

ESD (FICDM)

1.25 kV

Stresses at or above those listed under Absolute Maximum

Ratings may cause permanent damage to the product. This is a

stress rating only; functional operation of the product at these

or any other conditions above those indicated in the operational

section of this specification is not implied. Operation beyond

the maximum operating conditions for extended periods may

affect product reliability.

Table 9. Thermal Resistance

Package Type

RW-16

1

θ_JA

59.7

θ_JC

28.3

Unit

°C/W

¹Thermal impedance simulated values are based on a JEDEC 2S2P thermal

test board with no vias. See JEDEC JESD51.

ESD CAUTION

Rev. A | Page 7 of 27

ADM2795E

Data Sheet

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

V

1

2

3

4

5

6

7

8

16

V

DD2

DD1

GND

15 GND

1

2

TxD

DE

14

13

B

ADM2795E

V

DD2

TOP VIEW

RE

(Not to Scale) 12 GND

11

10 GND

2

RxD

NIC

A

2

GND

9 GND

1

NOTES

1. NIC = NOT INTERNALLY CONNECTED.

Figure 3. Pin Configuration

Table 10. Pin Function Descriptions

Pin No. Mnemonic Description

1

2

3

4

V_DD1

GND₁

TxD

DE

1.7 V to 5.5 V Flexible Logic Interface Supply.

Ground 1, Logic Side.

Transmit Data Input. Data to be transmitted by the driver is applied to this input.

Driver Output Enable. A high level on this pin enables the driver differential outputs, A and B. A low level places

them into a high impedance state.

5

RE

Receiver Enable Input. This pin is an active low input. Driving this input low enables the receiver, and driving it high

disables the receiver.

6

7

8

9

10

11

RxD

NIC

GND₁

GND₂

A

Receiver Output Data. This output is high when (A – B) > −30 mV and low when (A – B) < –200 mV.

Not Internally Connected. This pin is not internally connected.

Ground 1, Logic Side.

Isolated Ground 2, Bus Side.

Noninverting Driver Output/Receiver Input. When the driver is disabled, or when V_DD1or V_DD2is powered down,

Pin A is put into a high impedance state to avoid overloading the bus.

12

13

14

GND₂

V_DD2

B

Isolated Ground 2, Bus Side.

3 V to 5.5 V Power Supply. Pin 13 must be connected externally to Pin 16.

Inverting Driver Output/Receiver Input. When the driver is disabled, or when V_DD1or V_DD2is powered down, Pin B is

put into a high impedance state to avoid overloading the bus.

15

16

GND₂

V_DD2

Isolated Ground 2, Bus Side.

3 V to 5.5 V Power Supply. Pin 16 must be connected externally to Pin 13.

Rev. A | Page 8 of 27

Data Sheet

ADM2795E

TYPICAL PERFORMANCE CHARACTERISTICS

100

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

V

= V

= 5.5 V

I

, 54Ω LOAD

DD1

DD2

V

= V

= 5.5V

DD1

DD2

90

80

70

60

50

40

30

20

10

0

I

, 120Ω LOAD

DD2

I

, NO LOAD

DD2

I

DD1

–40

–20

0

20

40

60

80

100

120

–40

–20

0

20

40

60

80

100

120

TEMPERATURE (°C)

Figure 4. Supply Current (I_CC) vs. Temperature at R_L= 54 Ω, 120 Ω, and No

Load; Data Rate = 2.5 Mbps, V_DD1= 5.5 V, V_DD2= 5.5 V

Figure 7. Driver Differential Output Voltage vs. Temperature

60

0

V

= 1.7V, V

= 3.0V

DD1

DD2

–0.02

–0.04

–0.06

–0.08

–0.10

–0.12

–0.14

–0.16

50

40

30

20

10

0

I

, 54Ω LOAD

DD2

V

= 1.7V, V

= 5.5V, V

= 3.0V

= 5.5V

DD1

DD2

PIN A

V

DD1

PIN B

I

, 120Ω LOAD

DD2

V

DD1

PIN A

V

DD1

PIN B

I

, NO LOAD

DD2

I

DD1

–40

–20

0

20

40

60

80

100

120

TEMPERATURE (°C)

DRIVER OUTPUT HIGH VOLTAGE (V)

Figure 8. Driver Output Current vs. Driver Output High Voltage

Figure 5. Supply Current (I_CC) vs. Temperature at R_L= 54 Ω, 120 Ω, and No

Load; Data Rate = 2.5 Mbps, V_DD1= 1.7 V, V_DD2= 3.0 V

0.14

0.12

0.10

0.01

V

= 1.7V,

= 3.0V

–0.04

–0.09

–0.14

–0.19

–0.24

–0.29

–0.34

–0.39

DD1

DD2

V

= 1.7V, V

= 5.5V, V

= 3.0V

= 5.5V

DD1

DD2

0.08

0.06

0.04

0.02

0

PIN A

V

= 4.5V,

DD1

DD2

V

DD1

= 4.5V

PIN B

V

= 5.5V,

= 5.5V

DD1

DD2

PIN A

V

DD1

PIN B

0

5

10

15

20

25

0

1

2

3

4

5

6

DRIVER OUTPUT LOW VOLTAGE (V)

DIFFERENTIAL OUTPUT VOLTAGE (V)

Figure 9. Driver Output Current vs. Driver Output Low Voltage

Figure 6. Driver Output Current vs. Differential Output Voltage

Rev. A | Page 9 of 27

ADM2795E

Data Sheet

45

40

35

30

25

20

15

10

5

36

35

34

33

32

31

30

29

28

27

26

V

= V

= 5V

DD2

V

= V

= 5.5V

DD2

DD1

t_DPLH

t_DPHL

0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

–40

–20

0

20

40

60

80

100

120

RECEIVER OUTPUT LOW VOLTAGE (V)

TEMPERATURE (°C)

Figure 13. Receiver Output Current vs. Receiver Output Low Voltage

Figure 10. Driver Differential Propagation Delay vs. Temperature

6

V

= 5.0V,

= 5.0V

I

= –1mA

TxD

DD1

DD2

RxD

5

4

3

2

1

C1

V

OD

M1

V

= 1.8V,

= 3.3V

DD1

DD2

0

–55

B

C1 2.0V/DIV 1MΩ

: 500M

A CH1

2.12V

–25

5

35

65

95

125

W

M1 2.00V

100ns

TEMPERATURE (°C)

Figure 11. Driver Propagation Delay (Oscilloscope)

Figure 14. Receiver Output High Voltage vs. Temperature

–70

60

50

40

30

20

10

0

V

= V

= 5V

DD2

I

= –1mA

DD1

RxD

–60

–50

–40

–30

–20

–10

0

V

= 1.8V,

= 3.3V

DD1

DD2

V

= 5.0V,

= 5.0V

DD1

DD2

–55

–25

5

35

65

95

125

0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

TEMPERATURE (°C)

RECEIVER OUTPUT HIGH VOLTAGE (V)

Figure 15. Receiver Output Low Voltage vs. Temperature

Figure 12. Receiver Output Current vs. Receiver Output High Voltage

Rev. A | Page 10 of 27

Data Sheet

ADM2795E

140

120

100

80

t_PLH

t_PHL

A

B

2

V

OD

M1

60

RxD

40

20

3

0

–55

B

C1 2.0V/DIV 1MΩ

: 500M

A

CH3

2.56V

W

–25

5

35

65

95

125

100ns/DIV

1.0ns/pt

C2 2.0V/DIV 1MΩ

C3 2.0V/DIV 1MΩ

TEMPERATURE (°C)

M1 1.4V

100ns

Figure 19. Receiver Propagation Delay vs. Temperature

Figure 16. Receiver Propagation Delay (Oscilloscope)

250

200

150

100

50

A

B

2

PIN B

PIN A

V

OD

M1

RxD

3

0

B

C1 1.0V

C2 1.0V

1MΩ

: 500M OFFSET: 25.0V A CH3

2.56V

100ns/DIV

1.0ns/pt

W

15

JUNCTION TEMPERATURE (°C)

–55 –40 –25 –5

35 55 75 95 115 125 130 140

: 500M OFFSET: 25.0V

: 500M

C3 2.0V/DIV 1MΩ

M1 600mV 100ns

Figure 20. Receiver Performance with Input Common-Mode Voltage of 25 V

Figure 17. Input Capacitance (A, B) vs. Junction Temperature

0.14

0.12

0.10

0.08

80

70

60

50

EN55022

40

EN55022B

V

= 1.7V, V

= 5.5V, V

= 3.0V

= 5.5V

DD1

DD2

0.06

0.04

0.02

0

PIN A

V

PIN B

V

PIN A

V

PIN B

30

20

10

0

DD1

30M

100M

FREQUENCY (Hz)

1G

PIN VOLTAGE (V)

Figure 18. Radiated Emissions Profile with 120 pF Capacitor to GND₁on the

RxD Pin (Horizontal Scan, Data Rate = 2.5 Mbps, V_DD1= V_DD2= 5.0 V)

Figure 21. Short-Circuit Current over Fault Voltage Range

Rev. A | Page 11 of 27

ADM2795E

Data Sheet

45

40

35

30

25

20

15

10

5

700

600

500

400

300

200

100

0

100k

1M

10M

100M

1G

0

0.25

0.50

1.00

2.00

2.50

DPI FREQUENCY (Hz)

SIGNALING RATE (Mbps)

Figure 22. DPI IEC 62132-4 Noise Immunity with 100 nF and 10 μF

Decoupling on V_DD1

Figure 25. Receiver Input Differential Voltage (V_ID) vs. Signaling Rate

45

40

35

30

25

20

15

10

5

60

50

FALL TIME

40

RISE TIME

30

20

10

0

100k

1M

10M

100M

1G

10

100

1000

DPI FREQUENCY (Hz)

LOAD CAPACITANCE (pF)

Figure 23. DPI IEC 62132-4 Noise Immunity with 100 nF Decoupling on V_DD1

Figure 26. Receiver Output (RxD) Rise/Fall Time vs. Load Capacitance

45

40

35

30

25

20

15

10

5

0

100k

1M

10M

100M

1G

DPI FREQUENCY (Hz)

Figure 24. DPI IEC 62132-4 Noise Immunity with 100 nF and Decoupling on

V_DD2

Rev. A | Page 12 of 27

Data Sheet

ADM2795E

TEST CIRCUITS

V

DD2

S2

OUT

R

A

B

R

110Ω

L

|V

|

OD

TxD

DE

S1

C

L

V

OC

50pF

Figure 27. Driver Voltage Measurement

Figure 30. Driver Enable/Disable

375Ω

A

V

OUT

V

TST

|V

|

RE

OD3

B

60Ω

C

L

375Ω

Figure 28. Driver Voltage Measurement over Common-Mode Voltage Range

Figure 31. Receiver Propagation Delay

+1.5V

–1.5V

V

DD1

A

S1

C

L1

L2

R

L

S2

R

LDIFF

RE

C

V

OUT

L

B

RE INPUT

Figure 32. Receiver Enable/Disable

Figure 29. Driver Propagation Delay

Rev. A | Page 13 of 27

ADM2795E

Data Sheet

SWITCHING CHARACTERISTICS

V

DD1

DE

TxD

0.5V

t_ZL

0.5V

DD1

0V

B

0V

t_PHL

t_PLH

t_LZ

1/2 |V

|

OD

|V

|

0.5V

OD

A

DD2

A, B

V

+ 0.5V

– 0.5V

OL

V

OL

t_SKEW

= |t_PLH– t_PHL|

t_ZH

t_HZ

+V

OH

OUT

90% POINT

V

OH

0.5V

V

DIFF

10% POINT

0V

–V

OUT

t_R

t_F

Figure 33. Driver Propagation Delay, Rise/Fall Timing

Figure 35. Driver Enable/Disable Timing

V

DD1

RE

0.5V

t_ZL

0.5V

DD1

0V

A, B

0V

t_LZ

0.5V

DD1

RxD

V

+ 0.5V

t_PLH

t_PHL

OL

OUTPUT LOW

V

OL

t_HZ

V

OH

t_ZH

OUTPUT HIGH

OH

0.5V

DD1

V

– 0.5V

DD1

RxD

0V

OH

RxD

0.5V

DD1

t_SKEW

=

|t_PLH

–

t_PHL

|

OL

Figure 34. Receiver Propagation Delay

Figure 36. Receiver Enable/Disable Timing

Rev. A | Page 14 of 27

Data Sheet

ADM2795E

THEORY OF OPERATION

In choosing suitable EMC protection components, the system

designer is faced with two challenges: achieving compliance to

EMC regulations, and matching the dynamic breakdown

characteristics of the EMC protection to the RS-485 transceiver.

To overcome these challenges, the designer may need to run

multiple design, test, and printed circuit board (PCB) board

iterations, leading to a slower time to market and project budget

overruns.

RS-485 WITH ROBUSTNESS

The ADM2795E is a 3 V to 5.5 V RS-485/RS-422 transceiver

with robustness that reduces system failures when operating in

harsh application environments.

The ADM2795E is a RS-485/RS-422 transceiver that integrates

IEC 61000-4-5 Level 4 surge protection, allowing up to 4 kV of

protection on the RS-485 bus pins without the need for external

protection components such as transient voltage suppressors

(TVS) or TISP® surge protectors. The ADM2795E 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.

To reduce system cost and design complexity, the ADM2795E

provides certified integrated EMC protection and overvoltage

fault protection on the RS-485 bus pins. The ADM2795E

integrated EMC and overvoltage fault protection circuits are

optimally performance matched, saving the circuit designer

significant design and testing time.

The ADM2795E is an RS-485 transceiver that offers a defined

level of overvoltage fault protection in addition to IEC 61000-4-2

ESD, IEC 61000-4-4 EFT, and IEC 61000-4-5 surge protection

for the RS-485 bus pins.

Figure 37 shows an isolated EMC protected RS-485 circuit

layout example, which targets IEC 61000-4-2 ESD Level 4,

IEC 61000-4-4 EFT Level 4, and IEC 61000-4-5 surge protection

to Level 4 for the RS-485 bus pins. This circuit uses several

discrete components, including two TISP surge protectors, two

transient blocking units (TBUs), and one dual TVS. Due to the

integrated protection components of the ADM2795E, the PCB

area is significantly reduced when compared to a solution with

discrete EMC protection components.

INTEGRATED AND CERTIFIED IEC EMC SOLUTION

The driver outputs/receiver inputs of RS-485 devices often experi-

ence high voltage faults resulting from short circuits to power

supplies that exceed the −7 V to +12 V range specified in the

TIA/EIA-485-A standard. Typically, RS-485 applications require

costly external protection devices, such as positive temperature

coefficient (PTC) fuses, for operation in these harsh electrical

environments. In harsh electrical environments, system design-

ers also must consider common EMC problems, choosing

components to provide IEC 61000-4-2 ESD, IEC 61000-4-4

EFT, and IEC 61000-4-5 surge protection for the RS-485 bus pins.

DIGITAL ISOLATOR

100nF

RS-485

TRANSCEIVER

TISP

100nF

TVS

TBU

100nF

ADM2795E

Figure 37. ADM2795E Certified Integrated IEC 61000-4-5 Surge Solution, Saving the Designer Significant PCB Area

Rev. A | Page 15 of 27

ADM2795E

Data Sheet

Table 11. Miswire Protection Table Abbreviations

OVERVOLTAGE FAULT PROTECTION

Letter

Description

The ADM2795E is an RS-485 transceiver that offers fault

protection over a 3 V to 5.5 V V_DD2operating range without the

need for close examination of the logic pin state (TxD input and

H

L

X

High level for logic pin

Low level for logic pin

On or off power supply state

RE

the DE and

enable pins) of the RS-485 transceiver. The

transceiver is also fault protected over the entire extended

common-mode operating range of 25 V.

Table 12. High Voltage Miswire Protection

Supply

Inputs

Miswire Protection at

TxD RS-485 Outputs Pins^{1, 2}

The ADM2795E RS-485 driver outputs/receiver inputs are

protected from short circuits to any voltage within the range of

–42 V to +42 V ac/dc peak. The maximum short-circuit output

current in a fault condition is 250 mA. The RS-485 driver

includes a foldback current limiting circuit that reduces the driver

current at voltages above the 25 V common-mode range limit

of the transceiver (see Figure 21 in the Typical Performance

Characteristics section). This current reduction due to the

foldback feature allows better management of power dissipation

and heating effects.

RE

V_DD1V_DD2DE

X

H/L H/L H/L −42 V dc ≤ V_A≤ +42 V dc

H/L H/L H/L −42 V dc ≤ V_B≤ +42 V dc

H/L H/L H/L −42 V ac ≤ V_A≤ +42 V ac

H/L H/L H/L −42 V ac ≤ V_B≤ +42 V ac

¹This is the ac/dc peak miswire voltage between Pin A and GND₂, or Pin B and

GND₂, or between Pin A and Pin B.

²V_Arefers to the voltage on Pin A, and V_Brefers to the voltage on Pin B.

RS-485 NETWORK BIASING AND TERMINATION

For a high voltage miswire on the RS-485 A and B bus pins with

biasing and termination resistors installed, there is a current

path through the biasing network to the ADM2795E power

supply pin, V_DD2. To protect the ADM2795E in this scenario, the

device has an integrated V_DD2protection circuit.

42 V MISWIRE PROTECTION

The ADM2795E is protected against high voltage miswire

events when it operates on a bus that does not have RS-485

termination or bus biasing resistors installed. A typical miswire

event is where a high voltage 24 V ac/dc power supply is connected

directly to RS-485 bus pin connectors. The ADM2795E can

withstand miswiring faults of up to 42 V peak on the RS-485

bus pins with respect to GND₂without damage. Miswiring

protection is guaranteed on the ADM2795E RS-485 A and B

bus pins, and is guaranteed in the case of a hot swap of

connectors to the bus pins. Table 11 and Table 12 provide a

summary of the high voltage miswire protection offered by the

ADM2795E. The ADM2795E is tested with 42 V dc and with

24 V 20ꢀ rms, 50 Hz/60 Hz, with both a hot plug and dc

ramp test waveforms. The test is performed in both powered

and unpowered/floating power supply cases, and at a range of

The ADM2795E is a fault protected RS-485 device that also

features protection for its power supply pin. This means that the

current path through the R1 pull-up resistor does not cause

damage to the V_DD2pin, although the pull-up resistor itself can

be damaged if not appropriately power rated (see Figure 38).

The R1 pull-up resistor power rating depends on the miswire

voltage and the resistance value.

If there is a miswire between the A and B pins in the Figure 38

bus setup, the ADM2795E is protected, but the RT bus termina-

tion resistor can be damaged if not appropriately power rated.

The RT termination resistor power rating depends on the miswire

voltage and the resistance value.

RE

different states for the RS-485 TxD input and the DE and

enable pins. The RS-485 bus pins survive a high voltage miswire

from Pin A to GND₂, from Pin B to GND₂, and between Pin A

and Pin B.

V

DD1

DD2

RS-485

TRANSCEIVER

DIGITAL ISOLATOR

V

DD2

ADM2795E

RxD

RE

R

R1

390Ω

A

EMC

A

B

TRANSIENT

PROTECTION

CIRCUIT

RT

220Ω

DE

B

R2

390Ω

D

TxD

GND

2

1

ISOLATION

BARRIER

Figure 38. High Voltage Miswiring Protection for the ADM2795E with Bus Termination and Biasing Resistor

Rev. A | Page 16 of 27

Data Sheet

ADM2795E

humidity, temperature, barometric pressure, distance, and rate

of approach to the unit under test. This method is a better

representation of an actual ESD event but is not as repeatable.

Therefore, contact discharge is the preferred test method.

IEC ESD, EFT, AND SURGE PROTECTION

Electrical and electronic equipment must be designed to meet

system level IEC standards. The following are example system

level IEC standards:

During testing, the data port is subjected to at least 10 positive

and 10 negative single discharges with a minimum 1 sec interval

between each pulse. Selection of the test voltage is dependent on

the system end environment.



Process control and automation: IEC 61131-2

Motor control: IEC 61800-3

Building automation: IEC 60730-1

For data communication lines, these system level standards

specify varying levels of protection against the following three

types of high voltage transients:

Figure 39 shows the 8 kV contact discharge current waveform

as described in the IEC 61000-4-2 specification. Some of the

key waveform parameters are rise times of less than 1 ns and

pulse widths of approximately 60 ns.



IEC 61000-4-2 ESD

IEC 61000-4-4 EFT

IEC 61000-4-5 surge

I

PEAK

30A

90%

Each of these specifications defines a test method to assess the

immunity of electronic and electrical equipment against the

defined phenomenon. The following sections summarize each

of these tests. The ADM2795E is fully tested in accordance with

these IEC EMC specifications, and is certified IEC EMC

compliant.

16A

I

30ns

60ns

8A

Electrostatic Discharge (ESD)

10%

ESD is the sudden transfer of electrostatic charge between bodies

at different potentials caused by near contact or induced by an

electric field. ESD has the characteristics of high current in a

short time period. The primary purpose of the IEC 61000-4-2

test is to determine the immunity of systems to external ESD

events outside the system during operation. IEC 61000-4-2

describes testing using two coupling methods: contact discharge

and air gap discharge. Contact discharge implies a direct contact

between the discharge gun and the unit under test. During air

discharge testing, the charged electrode of the discharge gun is

moved toward the unit under test until a discharge occurs as an

arc across the air gap. The discharge gun does not make direct

contact with the unit under test. A number of factors affect the

results and repeatability of the air discharge test, including

TIME

60ns

30ns

t_R= 0.7ns TO 1ns

Figure 39. IEC 61000-4-2 ESD Waveform (8 kV)

Figure 40 shows an example test setup where the ADM2795E

evaluation board was tested to both contact discharge and air

discharge for the IEC 61000-4-2 ESD standard.

Testing was performed with the IEC ESD gun connected to the

local bus, GND₂. In testing to GND₂, the ADM2795E is robust

to IEC 61000-4-2 events and passes the highest level recognized

in the standard, Level 4, which defines a contact discharge

voltage of 8 kV and an air discharge voltage of 15 kV.

V

DD1

DD2

RS-485

TRANSCEIVER

DIGITAL ISOLATOR

ADM2795E

RxD

RE

R

EMC

A

B

IEC ESD

GUN

TRANSIENT

PROTECTION

CIRCUIT

DE

D

TxD

GND

2

1

ISOLATION

BARRIER

Figure 40. IEC 61000-4-2 ESD Testing to GND₁or GND₂

Rev. A | Page 17 of 27

ADM2795E

Data Sheet

Testing was also performed with the IEC ESD gun connected to

the logic side GND₁. Testing to GND₁demonstrates the

robustness of the ADM2795E isolation barrier. The isolation

barrier is capable of withstanding IEC 61000-4-2 ESD to 9 kV

contact and to 8 kV air. Testing was performed in normal

transceiver operation, with the ADM2795E clocking data at

2.5 Mbps. Table 13 and Table 16 summarize the certified test

results.

in IEC 61000-4-4 attempts to simulate the interference resulting

from these types of events.

Figure 42 shows the EFT 50 Ω load waveforms. The EFT

waveform is described in terms of a voltage across a 50 Ω

impedance from a generator with a 50 Ω output impedance. The

output waveform consists of a 15 ms burst of 5 kHz high voltage

transients repeated at 300 ms intervals. The EFT test is also

performed with a 750 μs burst at a higher 100 kHz frequency.

Each individual pulse has a rise time of 5 ns and a pulse duration

of 50 ns, measured between the 50ꢀ point on the rising and falling

edges of the waveform. The total energy in a single EFT pulse is

similar to that in an ESD pulse.

Table 13. IEC 61000-4-2 Certified Test Results

ESD Gun

Connected to

Certified

Result

IEC 61000-4-2 Test Result

GND₂

15 kV (air), 8 kV (contact),

Level 4 protection

Yes

V

PEAK

100%

90%

GND₁

Withstands 8 kV (air), 9 kV Yes

(contact)

t_R= 5ns ± 30%

SINGLE

Figure 41 shows the 8 kV contact discharge current waveform

from the IEC 61000-4-2 standard compared to the HBM ESD

8 kV waveform. Figure 41 shows that the two standards each

specify a very different waveform shape and peak current. The

peak current associated with a IEC 61000-4-2 8 kV pulse is

30 A, while the corresponding peak current for HBM ESD is

more than five times less, at 5.33 A. The other difference is the

rise time of the initial voltage spike, with IEC 61000-4-2 ESD

having a much faster rise time of 1 ns, compared to the 10 ns

associated with the HBM ESD waveform. The amount of power

associated with an IEC ESD waveform is much greater than that

of an HBM ESD waveform. The ADM2795E with IEC 61000-4-2

ESD ratings is better suited for operation in harsh environments

compared to other RS-485 transceivers that state varying levels of

HBM ESD protection.

t_D= 5ns ± 30%

PULSE

50%

10%

t_D

t_R

TIME (ns)

15ms

BURST

OF PULSES

TIME (ms)

I

V

PEAK

300ms

30A

90%

REPETITIVE

BURSTS

IEC 61000-4-2 ESD 8kV

16A

I

30ns

TIME (ms)

Figure 42. IEC 61000-4-4 EFT 50 Ω Load Waveforms

8A

5.33A

During testing, these EFT fast burst transients are coupled onto

the communication lines using a capacitive clamp, as shown in

Figure 43. The EFT is capacitively coupled onto the communica-

tion lines by the clamp rather than direct contact. This clamp

also reduces the loading caused by the low output impedance of

the EFT generator. The coupling capacitance between the clamp

and cable depends on cable diameter, shielding, and insulation

on the cable. The EFT clamp edge is placed 50 cm from the

equipment under test (EUT) (ADM2795E evaluation board).

The EFT generator is set up for either 5 kHz or 100 kHz repeti-

tive EFT bursts. The ADM2795E was tested in both 5 kHz and

100 kHz test setups.

60ns

HBM ESD 8kV

10%

TIME

10ns

t_R= 0.7ns TO 1ns

30ns

60ns

Figure 41. IEC 61000-4-2 ESD Waveform (8 kV) Compared to HBM ESD

Waveform (8 kV)

Electrical Fast Transients (EFTs)

EFT testing involves coupling a number of extremely fast transient

impulses onto the signal lines to represent transient disturbances

(associated with external switching circuits that are capacitively

coupled onto the communication ports), which may include

relay and switch contact bounce or transients originating from

the switching of inductive or capacitive loads—all of which are

very common in industrial environments. The EFT test defined

With the EFT clamp connected to GND₂, the ADM2795E is

robust to IEC 61000-4-4 EFT transients and protects against the

highest level recognized in the standard, Level 4, which defines

Rev. A | Page 18 of 27

Data Sheet

ADM2795E

a voltage level of 2 kV. With the IEC 61000-4-4 EFT clamp con-

nected to GND₁, the ADM2795E is robust to IEC 61000-4-4

EFT transients and withstands up to 2 kV. Testing was performed

in normal transceiver operation, with the ADM2795E clocking

data at 2.5 Mbps. The results shown in Table 14 are valid for a

setup with or without an RS-485 cable shield connection to

GND₂. The ADM2795E withstands up to 2 kV IEC 61000-4-4

EFT without damage. Table 14 and Table 16 summarize the

certified test results.

defines waveforms, test methods, and test levels for evaluating

immunity against these destructive surges.

The waveforms are specified as the outputs of a waveform genera-

tor in terms of open circuit voltage and short-circuit current.

Two waveforms are described. The 10 μs/700 ꢁs combination

waveform is used to test ports intended for connection to symmet-

rical communication lines: for example, telephone exchange lines.

The 1.2 μs/50 ꢁs combination waveform generator is used in all

other cases, in particular short distance signal connections. For

RS-485 ports, the 1.2 μs/50 ꢁs waveform is predominantly used

and is described in this section. The waveform generator has an

effective output impedance of 2 Ω; therefore, the surge transient

has high currents associated with it.

Table 14. IEC 61000-4-4 Certified Test Results

EFT Clamp

Connected to

Certified

Result

IEC 61000-4-4 Test Result

2 kV Level 4 protection

Withstands 2 kV

GND₂

GND₁

Yes

Figure 44 shows the 1.2 μs and 50 ꢁs surge transient waveform.

ESD and EFT have similar rise times, pulse widths, and energy

levels; however, the surge pulse has a rise time of 1.25 ꢁs and the

pulse width is 50 ꢁs. Additionally, the surge pulse energy is

three to four orders of magnitude larger than the energy in an

ESD or EFT pulse. Therefore, the surge transient is considered

the most severe of the EMC transients.

Surge

Surge transients are caused by overvoltage from switching or

lightning transients. Switching transients can result from power

system switching, load changes in power distribution systems,

or various system faults such as short circuits. Lightning

transients can be a result of high currents and voltages injected

into the circuit from nearby lightning strikes. IEC 61000-4-5

V

DD2

DD1

RS-485

TRANSCEIVER

IEC EFT

GENERATOR

5kHz, 100kHz

DIGITAL ISOLATOR

ADM2795E

RxD

RE

R

A

EMC

TRANSIENT

PROTECTION

CIRCUIT

RS-485

CABLE

DE

B

IEC EFT

CLAMP

D

TxD

GND

2

1

RS-485 CABLE SHIELD

ISOLATION

BARRIER

Figure 43. IEC 61000-4-4 EFT Testing to GND₁or GND₂

V

PEAK

100%

90%

t₁= 1.2µs ± 30%

t₂= 50µs ± 20%

50%

10%

t₂

30% MAX

TIME (µs)

t₁

Figure 44. IEC 61000-4-5 Surge 1.2 μs/50 ꢀs Waveform

Rev. A | Page 19 of 27

ADM2795E

Data Sheet

V

DD2

DD1

RS-485

TRANSCEIVER

DIGITAL ISOLATOR

ADM2795E

RxD

RE

R

COUPLING NETWORK

A

B

80Ω

EMC

IEC SURGE

GENERATOR

TRANSIENT

PROTECTION

CIRCUIT

CD

DE

80Ω

D

TxD

GND

2

1

ISOLATION

BARRIER

Figure 45. IEC 61000-4-5 Surge Testing to GND₁or GND₂

IEC 61000-4-5 surge testing involves using a coupling/decoupling

network (CDN) to couple the surge transient into the RS-485 A

and B bus pins. The coupling network for a half-duplex RS-485

device consists of an 80 ꢂ resistor on both the A and B lines

and a coupling device. The total parallel sum of the resistance is

40 Ω. The coupling device can be capacitors, gas arrestors, clamp-

ing devices, or any method that allows the EUT to function

correctly during the applied test. During the surge test, five

positive and five negative pulses are applied to the data ports

with a maximum time interval of one minute between each pulse.

The standard states that the device must be set up in normal

operating conditions for the duration of the test. Figure 45

shows the test setup for surge testing. Testing was performed in

normal transceiver operation, with the ADM2795E clocking

data at 2.5 Mbps.

up to 4 kV surge. The ADM2795E withstands up to 4 kV IEC

61000-4-5 surge without damage and with no bit errors in data

communications. Testing to GND₁demonstrates the robustness

of the ADM2795E isolation barrier. Table 15 and Table 16

summarize the certified test results.

Table 15. IEC 61000-4-5 Certified Test Results

Surge Generator

Connected to

IEC 61000-4-5 Test

Result

Certified

Result

GND₂

GND₁

4 kV Level 4 protection

Withstands 4 kV

Yes

Table 16 summarizes the ADM2795E performance and

classification achieved for the noted IEC system level EMC

standards.

The performance corresponds to each classification as follows:

With the IEC surge generator connected to GND₂, the

ADM2795E is robust to IEC 61000-4-5 events and protects

against the highest level recognized in the standard, Level 4,

which defines a peak voltage of 4 kV.



Class A—normal operation

Class B—temporary loss of performance (bit errors)

Class C—system needs reset

Class D—permanent loss of function

With the IEC surge generator connected to GND₁, the

ADM2795E is robust to IEC 61000-4-5 events and withstands

Table 16. Summary of Certified EMC System Level Classifications for the ADM2795E

Test

Ground Connection

Classification

Class A

Class B

Highest Pass Level

IEC 61000-4-5 Surge

GND₁

GND₂

4 kV

IEC 61000-4-4 Electrical Fast Transient (EFT)

IEC 61000-4-2 Electrostatic Discharge (ESD)

IEC 61000-4-6 Conducted RF Immunity

GND₁

GND₂

GND₁

GND₂

GND₁

GND₂

Class B

Class A

2 kV

8 kV (air), 9 kV (contact)

15 kV (air), 8 kV (contact)

10 V/m rms

30 V/m

IEC 61000-4-3 Radiated RF Immunity

IEC 61000-4-8 Magnetic Immunity

100 A/m

Rev. A | Page 20 of 27

Data Sheet

ADM2795E

Table 17. IEC 61000-4-6 EUT and Equipment

IEC CONDUCTED, RADIATED, AND MAGNETIC

IMMUNITY

Parameter

Details

IEC 61000-4-6

Clamp

IEC 61000-4-6 Test

Level

Schaffner KEMZ 801, placed at 30 cm

from the EUT

Level 3, 0.15 MHz to 80 MHz, 10 V/m rms,

80% amplitude modulated (AM) by a

1 kHz sinusoidal

EVAL-ADM2795EEBZ

2.5 Mbps

9 V battery at V_DD1and V_DD2, regulated on

EUT to 5 V

5 m, Unitronic® Profibus, 22 American

wire gauge (AWG )

120 Ω resistor at both cable ends

Pass: data at receiver with a pulse width

distortion within 10% of mean

IEC 61000-4-6 Conducted RF Immunity

The IEC 61000-4-6 conducted immunity test is applicable to

products that operate in environments where RF fields are

present and that are connected to mains supplies or other

networks (signal or control lines). The source of conducted

disturbances are electromagnetic fields, emanating from RF

transmitters that may act on the whole length of cables

connected to installed equipment.

EUT

EUT Data Rate

EUT Power

Cable Between EUT

In the IEC 61000-4-6 test, an RF voltage is swept/stepped from

150 kHz to 80 MHz or 100 MHz. The RF voltage is amplitude

modulated 80ꢀ at 1 kHz. One ADM2795E evaluation board

was tested to Level 3, which is the highest test level of 10 V. For

IEC 61000-4-6 testing, the stress signal is applied by using the

clamp detailed in Table 17. The clamp is placed on the communica-

tions cable between two ADM2795E transceivers. For all testing,

the equipment and EUT setup are as described in Table 17 and

Figure 46.

Cable Termination

Pass/Fail Criteria

Table 18. IEC 61000-4-6 Certified Test Results

Clamp

Location

from EUT

(cm)

IEC 61000-4-6

Current Test

Cable

Shield

Return

Path

Frequency

(MHz)

Certified

Result

Table 17 shows the test results where the EUT passed IEC

61000-4-6 to Level 3. For all of the tests, the IEC 61000-4-6

clamp was placed at the EVAL-ADM2795EEBZ EUT, and the

cable shield was either floating or Earth grounded. The second

EVAL-ADM2795EEBZ (auxiliary equipment) was placed on the

network to terminate the communications bus. The IEC 61000-4-6

generator clamp was either connected to GND₁or GND₂of the

ADM2795E EUT to provide a return current path for the IEC

61000-4-6 transient current.

30

Floating GND₁

Earthed GND₁

Floating GND₂

Earthed GND₂

0.15 to 80

Pass

The ADM2795E evaluation board is tested and certified to pass

IEC 61000-4-6 conducted RF immunity testing to Level 3 at

10 V/m rms, in a variety of configurations as described in

Table 16 and Table 17.

V

DD1

DD2

RS-485

DIGITAL ISOLATOR

TRANSCEIVER

ADM2795E

IEC

EUT

AUXILIARY

61000-4-6

EQUIPMENT

RxD

RE

RxD

RE

GENERATOR

R

A

B

A

EMC

TRANSIENT

PROTECTION

CIRCUIT

TRANSIENT

PROTECTION

CIRCUIT

R

DE

T

B

IEC

61000-4-6

D

TxD

CLAMP

GND

2

GND

2

GND

1

RS-485 CABLE SHIELD

1

ISOLATION

BARRIER

Figure 46. IEC 61000-4-6 Conducted RF Immunity Example Test Setup Testing to GND₁or GND₂

Rev. A | Page 21 of 27

ADM2795E

Data Sheet

IEC 61000-4-3 Radiated RF Immunity

IEC 61000-4-8 Magnetic Immunity

Testing to IEC 61000-4-3 ensures that electronic equipment is

immune to commonly occurring radiated RF fields. Some

commonly occurring unintentional RF emitting devices in an

industrial application are electric motors and welders.

Testing to IEC 61000-4-8 ensures that electronic equipment is

immune to commonly occurring magnetic fields. The source of

magnetic fields in typical industrial communication applications is

power line current or 50 Hz/60 Hz transformers in close proximity

to the equipment.

In the IEC 61000-4-3 test, a radiated RF field is generated by an

antenna in a shielded anechoic chamber using a precalibrated

field, swept from 80 MHz to 2.7 GHz. The RF voltage is

amplitude modulated 80ꢀ at 1 kHz. Each face of the EUT is

subjected to vertical and horizontal polarizations.

In the IEC 61000-4-8 test, a controlled magnetic field of defined

field strength is produced by driving a large coil (induction coil)

with a test current generator. The EUT is placed at the center of

the induction coil, subjecting the EUT to a magnetic field.

Figure 47 shows the test setup with the EVAL-ADM2795EEBZ,

the EUT, placed in an anechoic chamber, powered with two 9 V

batteries. The EVAL-ADM2795EEBZ on board regulators

power V_DD1at 5.0 V and V_DD2at 5.0 V. The EVAL-ADM2795EEBZ

is loaded with a 120 ꢂ termination resistor for the duration of

the test. A pattern generator provides a 2.5 Mbps data input to

the ADM2795E TxD pin. The ADM2795E receiver output

(RxD) is monitored with an oscilloscope.

Figure 48 shows the test setup with the EVAL-ADM2795EEBZ,

the EUT, placed in an anechoic chamber, powered with two 9 V

batteries. The EVAL-ADM2795EEBZ on board regulators power

V_DD1at 5.0 V and V_DD2at 5.0 V. The EVAL-ADM2795EEBZ is

loaded with a 120 ꢂ termination resistor for the duration of the

test. A pattern generator provides a 2.5 Mbps data input to the

ADM2795E TxD pin. The ADM2795E receiver output (RxD) is

monitored with an oscilloscope.

The pass criteria chosen is less than a 10ꢀ change in the bit

width of the RxD signal in the presence of the IEC 61000-4-3

radiated RF field.

The pass criteria chosen is less than a 10ꢀ change in the bit

width of the RxD signal in the presence of the IEC 61000-4-8

magnetic field.

The ADM2795E evaluation board is tested and certified to pass

IEC 61000-4-3 radiated RF immunity testing to Level 4 (30 V/m).

Level 4 is the highest level specified in the IEC 61000-4-3

standard.

The ADM2795E evaluation board is tested and certified to pass

IEC 61000-4-8 magnetic immunity testing to Level 5 (100 A/m).

Level 5 is the highest level specified in the IEC 61000-4-8

standard.

ANECHOIC

CHAMBER

EUT

TESTED ON ALL FOUR SIDES

RF ABSORBING

MATERIAL

EUT

INDUCTION LOOP

EVAL-ADM2795EEBZ

V

9V

V

9V

V

DD2

9V

DD1

DD2

9V

DD1

EVAL-ADM2795EEBZ

TRANSMIT

ANTENNA

BATTERY BATTERY

IEC 61000-4-8

TEST CURRENT

GENERATOR

EUT

ANTENNA AT

1 METER TO 3 METERS

FROM EUT

ISOLATION

BARRIER

ISOLATION

BARRIER

POWER MONITOR

AND AMPLIFIER

OSCILLOSCOPE MONITORING

RxD RECEIVER OUTPUT

OSCILLOSCOPE MONITORING

RxD RECEIVER OUTPUT

PATTERN GENERATOR

TxD DRIVER INPUT

PATTERN GENERATOR

TxD DRIVER INPUT

Figure 47. Testing for IEC 61000-4-3 Radiated RF Immunity

Figure 48. Testing for IEC 61000-4-8 Magnetic Immunity

Rev. A | Page 22 of 27

Data Sheet

ADM2795E

APPLICATIONS INFORMATION

Performance to the IEC 62132-4 standard was evaluated for the

ADM2795E and compared to other isolators/transceivers

available in the market. The ADM2795E noise immunity

performance exceeds that of other similar products. The

ADM2795E maintains excellent performance over frequency,

but other isolation products exhibit bit errors in the 200 MHz to

700 MHz frequency band.

RADIATED EMISSIONS AND PCB LAYOUT

The ADM2795E meets stringent electromagnetic interference

(EMI) emissions targets (EN55022 Class B) with minimal PCB

layout considerations. To achieve a 6 dBμV/m margin from

EN55022 Class B limits, add a 120 pF, 0603 body size capacitor

on the PCB trace connected to the RxD pin and GND₁(see

Figure 49). Place the capacitor at 5 mm from the RxD pin for

optimal performance. The ADM2795E evaluation board user

guide provides an example PCB layout. Figure 18 shows a typical

performance plot of the ADM2795E EN55022 radiated emissions

profile (with a 120 pF capacitor to GND₁on the RxD pin).The

effect of adding load capacitance on the RxD pin is shown in

the typical waveform rise and fall times in Figure 26.

FULLY RS-485 COMPLIANT OVER AN EXTENDED

25 V COMMON-MODE VOLTAGE RANGE

The ADM2795E is an RS-485 transceiver that offers an extended

common-mode input range of 25 V across an operating voltage

range of 3 V to 5.5 V, while still meeting or exceeding compliance

with TIA/EIA RS-485/RS-422 standards, which specify a bus

differential voltage of at least 1.5 V across the common-mode

voltage range. In addition, when powered at greater than 4.5 V

NOISE IMMUNITY

Direct power injection (DPI) measures the ability of a

component to reject noise injected onto the power supply or

input pins. The ADM2795E was tested to the DPI IEC 62132-4

standard, with a high power noise source capacitively coupled

into either the V_DD1or V_DD2power supply pin. The noise source

was swept through a 300 kHz to 1 GHz frequency band. During

DPI IEC 62132-4 testing, the ADM2795E TxD pin was clocked

at 2.5 Mbps, and the clock data output on the RxD pin was

monitored for errors (loopback test mode). The fail criteria was

defined as greater than 10ꢀ change in the bit width of the

RxD signal.

V_DD2, the ADM2795E driver output is a minimum 2.1 V |V_OD|,

meeting the requirements for a Profibus compliant RS-485

driver. The extended common-mode input voltage range of

25 V improves system robustness over long cable lengths, where

large differences in ground potential between RS-485 transceivers

are possible. The extended common-mode input voltage range

of 25 V improves data communication reliability in noisy

environments over long cable lengths where ground loop

voltages are possible.

1.7 V TO 5.5 V V_DD1LOGIC SUPPLY

Figure 50 shows a test setup, with the DPI noise source injected

through a 6.8 nF capacitor on the ADM2795E V_DD1power

supply pin. Figure 22 to Figure 24 in the Typical Performance

Characteristics section show the fail point for the ADM2795E

across the noise power (dBm) vs. DPI frequency (Hz). Figure 21

shows that the addition of a 10 μF decoupling capacitor, in

addition to the standard 100 nF decoupling capacitor, improves

low frequency noise immunity.

The ADM2795E features a logic supply pin, V_DD1, for flexible

digital interface operational to voltages as low as 1.7 V. The

RE

V_DD1pin powers the logic inputs (TxD input, and DE and

control pins) and the RxD output. These pins interface with

logic devices such as universal asynchronous receiver/transmitters

(UARTs), application specific integrated circuits (ASICs), and

microcontrollers. Many of these devices use power supplies

significantly lower than 5 V.

100nF

V

DD2

DD1

GND

B

1

2

TxD

DE

V

DD2

ADM2795E

100nF

RE

GND

A

RxD

120pF

NIC

GND

2

GND

1

Figure 49. Recommended PCB Layout to Meet EN55022 Class B Radiated Emissions

Rev. A | Page 23 of 27

ADM2795E

Data Sheet

DPI

NOISE SOURCE

INJECTION

TWO FERRITES

BLMBD102SN1

6.8nF

V

5V

V

DD2

5V

DD1

V

DD2

DD1

220µH

C1

10µF

C2

100nF

GND

1

MINIMUM 400Ω IMPEDANCE

ACROSS 300kHz TO 1GHz RANGE

ADM2795E

2.5Mbps

CLOCK

RS-485A

A

TxD

RxD

60Ω

B

RS-485B

NOTES

1. SIMPLIFIED DIAGRAM, ALL PINS NOT SHOWN.

Figure 50. Typical Setup for DPI IEC 62132-4 Noise Immunity Test

TRUTH TABLES

RECEIVER FAIL-SAFE

Table 20 and Table 21 use the abbreviations shown in Table 19.

The receiver input includes a fail-safe feature that guarantees a

logic high RxD output when the A and B inputs are floating,

open circuit, or short circuit. A logic high RxD output is guaran-

teed in a terminated transmission line with all drivers disabled.

This fail-safe RxD guaranteed output logic high is implemented

by setting the receiver input threshold between −30 mV and

−200 mV. If the differential receiver input voltage (A − B) is

greater than or equal to −30 mV, RxD is logic high. If A − B is

less than or equal to −200 mV, RxD is logic low. In the case of a

terminated bus with all transmitters disabled, the receiver

differential input voltage is pulled to 0 V by the termination.

With the receiver thresholds of the ADM2795E, this results in a

RxD output logic high with a 30 mV minimum noise margin.

RE

V_DD1supplies the DE, TxD, , and RxD pins only.

Table 19. Truth Table Abbreviations

Letter

Description

H

I

L

High level

Indeterminate

Low level

X

Z

NC

Any state

High impedance (off)

Disconnected

Table 20. Transmitting Truth Table

Supply Status

Inputs

Outputs

RS-485 DATA RATE AND BUS CAPACITANCE

V_DD2

On

Off

V_DD1

On

Off

On

Off

DE

H

L

H

L

TxD

H

L

X

H

L

X

A

H

L

Z

I

Z

B

L

H

Z

I

Z

The data rate and bus node capability of the ADM2795E are

dependent on the operating temperature of the device. As the

operating temperature of the ADM2795E is increased, the capaci-

tance of the ADM2795E integrated EMC protection circuitry is

also increased. The driver output structures of the ADM2795E

can be simplified as low-pass filter structures, with a given

resistance and capacitance. As the operating temperature increases,

the capacitance increases. The low-pass filter effectively works

to decrease the maximum data rate that can be driven on the

RS-485 bus pins.

X

Table 21. Receiving Truth Table

Supply Status Inputs

INSULATION WEAR OUT

Outputs

The lifetime of insulation caused by wear out is determined by

its thickness, material properties, and the voltage stress applied.

It is important to verify that the product lifetime is adequate at

the application working voltage. The working voltage supported

by an isolator for wear out may not be the same as the working

voltage supported for tracking. The working voltage applicable

to tracking is specified in most standards.

RE

V_DD2

On

Off

V_DD1

On

Off

On

Off

On

Off

On

Off

A − B

RxD

>−0.03 V

<−0.2 V

>−0.03 V

<−0.2 V

−0.2 V < A − B < −0.03 V

Inputs open/shorted

X

L

H

L

I

H

I

Z

I

Testing and modeling show that the primary driver of long-

term degradation is displacement current in the polyimide

insulation causing incremental damage. The stress on the insula-

tion can be broken down into broad categories, such as dc

stress, which causes very little wear out because there is no

H

L or NC

I

Rev. A | Page 24 of 27

Data Sheet

ADM2795E

displacement current, and an ac component time varying

voltage stress, which causes wear out.

This V_RMSvalue is the working voltage used together with the

material group and pollution degree when looking up the

creepage required by a system standard.

The ratings in certification documents are typically based on

60 Hz sinusoidal stress because this reflects isolation from the

line voltage. However, many practical applications have

combinations of 60 Hz ac and dc across the barrier as shown in

Equation 1. Because only the ac portion of the stress causes

wear out, the equation can be rearranged to solve for the ac rms

voltage, as shown in Equation 2. For insulation wear out with the

polyimide materials used in the ADM2795E, the ac rms voltage

determines the product lifetime.

To determine if the lifetime is adequate, obtain the time varying

portion of the working voltage. To obtain the ac rms voltage,

use Equation 2.

2

V_{AC RMS}



V_RMS V_DC

V_AC

466² 400²

RMS

V

_{AC RMS}= 240 V rms

2

In this case, the ac rms voltage is simply the line voltage of

240 V rms. This calculation is more relevant when the

waveform is not sinusoidal. The value is compared to the limits

for working voltage in Table 8 for the expected lifetime, less

than a 60 Hz sine wave, and it is well within the limit for a

50-year service life.

(1)

V_RMS



V_AC

 V_DC

RMS

or

2

(2)

V_{AC RMS}



V_RMSV_DC

where:

V

_RMSis the total rms working voltage.

_{AC RMS}is the time varying portion of the working voltage.

_DCis the dc offset of the working voltage.

Note that the dc working voltage limit in Table 8 is set by the

creepage of the package as specified in IEC 60664-1. This value

can differ for specific system level standards.

Calculation and Use of Parameters Example

HOT SWAP CAPABILITY

The following example frequently arises in power conversion

applications. Assume that the line voltage on one side of the

isolation is 240 V ac rms and a 400 V dc bus voltage is present

on the other side of the isolation barrier. The isolator material is

polyimide. To establish the critical voltages in determining the

creepage, clearance, and lifetime of a device, see Figure 51 and

the following equations.

When a PCB is inserted into a hot (or powered) backplane,

differential disturbances to the data bus can lead to data errors.

The ADM2795E was lab tested to ensure that the RS-485 A and

B bus pins do not output spurious data during a power-up/power-

down event, which simulates a PCB hot insertion. The power

supply ramp test rates were 0 V to 5 V in 300 μs (fast ramp rate),

and 0 V to 5 V in 9.5 ms (slow ramp rate). For these ramp rates,

the RS-485 A and B outputs were monitored and no output

glitches were observed.

ROBUST HALF-DUPLEX RS-485 NETWORK

V

AC RMS

Figure 52 shows a robust isolated RS-485 communications

network, with bus communications running over 1000 feet of

cabling. Over long cable runs with multiple RS-485 nodes, a

number of hazards can either corrupt data communication or

even cause permanent damage to the RS-485 interface. The

ADM2795E provides robust protection against high voltage

faults to bus power supplies and EMC transients, such as an

IEC 61000-4-5 surge. In addition, the ADM2795E has an

extended common-mode input range of 25 V, which allows

25 V of ground potential difference between the isolated

GND₂pins of two or more ADM2795E devices.

V

DC

PEAK

RMS

TIME

Figure 51. Critical Voltage Example

The working voltage across the barrier from Equation 1 is

2

V_RMS

V_RMS 240² 400²

_RMS= 466 V



V_AC

 V_DC

RMS

V

Rev. A | Page 25 of 27

ADM2795E

Data Sheet

24V

POWER

SUPPLY

–

+

V

DD1

DD2

MISWIRE

TO A 24V

SUPPLY

EMC

TRANSIENT

RS-485

DIGITAL ISOLATOR

TRANSCEIVER

ADM2795E

RxD

RE

R

RxD

RE

A

B

A

EMC

TRANSIENT

PROTECTION

CIRCUIT

TRANSIENT

PROTECTION

CIRCUIT

R

DE

T

DE

B

D

TxD

GND

2

GND

2

GND

1

GND

1

ISOLATION

BARRIER

DD1

V

DD2

V

DD2

DD1

RS-485

TRANSCEIVER

RS-485

TRANSCEIVER

DIGITAL ISOLATOR

ADM2795E

RxD

RE

RxD

RE

R

A

B

A

B

EMC

TRANSIENT

PROTECTION

CIRCUIT

TRANSIENT

PROTECTION

CIRCUIT

DE

D

TxD

GND

2

GND

2

GND

1

GND

COMMUINICATION

WITH ±25V

POTENTIAL DIFFERENCE

BETWEEN ISOLATED

BUS GROUNDS

1

ISOLATION

BARRIER

Figure 52. Robust Half-Duplex Isolated RS-485 Communication Network

Rev. A | Page 26 of 27

Data Sheet

ADM2795E

OUTLINE DIMENSIONS

10.50 (0.4134)

10.10 (0.3976)

16

1

9

8

7.60 (0.2992)

7.40 (0.2913)

10.65 (0.4193)

10.00 (0.3937)

0.75 (0.0295)

0.25

(0.0098)

1.27 (0.0500)

BSC

45°

2.65 (0.1043)

2.35 (0.0925)

0.30 (0.0118)

0.10 (0.0039)

8°

0°

COPLANARITY

0.10

SEATING

PLANE

0.51 (0.0201)

0.31 (0.0122)

1.27 (0.0500)

0.40 (0.0157)

0.33 (0.0130)

0.20 (0.0079)

COMPLIANT TO JEDEC STANDARDS MS-013-AA

CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS

(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR

REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.

Figure 53. 16-Lead Standard Small Outline Package [SOIC_W]

Wide Body

(RW-16)

Dimensions shown in millimeters and (inches)

ORDERING GUIDE

Temperature

Range

Package

Ordering

Quantity

Model¹

Package Description

Option

RW-16

ADM2795EBRWZ

ADM2795EBRWZ-RL7

ADM2795EARWZ

ADM2795EARWZ-RL7

EVAL-ADM2795EEBZ

−40°C to +125°C

−40°C to +85°C

16-Lead Standard Small Outline Package [SOIC_W]

16-Lead Standard Small Outline Package [SOIC_W], 7” Reel

16-Lead Standard Small Outline Package [SOIC_W]

16-Lead Standard Small Outline Package [SOIC_W] , 7”Reel

Evaluation Board

400

¹Z = RoHS Compliant Part.

registered trademarks are the property of their respective owners.

D14129-0-3/17(A)

Rev. A | Page 27 of 27


型号：	ADM2795EBRWZ
厂家：	ADI
描述：	Robust 5 kV RMS Isolated RS-485/RS-422 Transceiver with Level 4 EMC and Full ±42 V Protection 驱动光电二极管接口集成电路驱动器
文件：	总28页 (文件大小：636K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

ADM2795EBRWZ [ADI]

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ADM2914-1SRQZEP

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