ISL32741EVAL1Z_技术文档

DATASHEET

ISL32741E

FN8944

Rev.2.00

Nov 30, 2017

PROFIBUS Compliant 6kV VDE-Reinforced Isolated RS-485 Transceiver

The ISL32741E is a galvanically isolated, high-speed

differential bus transceiver, designed for bidirectional

data communication on balanced transmission lines. The

device uses Giant Magnetoresistance (GMR) as its

isolation technology.

Features

• 40Mbps data rate

• 6kV

isolation/1000V working voltage

RMS

• 12.8kV surge immunity

• 3V to 5V power supplies

• 20ns propagation delay

• 5ns pulse skew

The part is available in a 16 Ld SOICW package with

true 8mm creepage distance.

The ISL32741E is PROFIBUS compliant, including the

rigorous PROFIBUS differential output voltage

specifications.

• 50kV/µs (typical), 30kV/µs (minimum)

common-mode transient immunity

A unique ceramic/polymer composite barrier provides

6kV reinforced isolation and 44,000 years of barrier life.

• 15kV ESD protection

The device is compatible with 3V and 5V input supplies,

allowing an interface to standard microcontrollers

without additional level shifting.

• Low EMC footprint

• Thermal shutdown protection

• Temperature ranges available

Current limiting and thermal shutdown features protect

against output short circuits and bus contention that may

cause excessive power dissipation. Receiver inputs are a

full fail-safe design, ensuring a logic high R-output if

A/B are floating or shorted.

• -40°C to +85°C (EIBZ) and

-40°C to +125°C (EFBZ)

• Meets or exceeds ANSI RS-485 and ISO

8482:1987(E)

Applications

• PROFIBUS compliant

• PROFIBUS-DP and RS-485 networks

• 0.3” true 8mm 16 Ld SOICW package

• UL 1577 recognized

• Factory automation

• Building environmental control systems

• Industrial/process control networks

• Equipment covered under IEC 61010-1 Edition 3

• VDE V 0884-10 certified

Related Literature

• For a full list of related documents, visit our website

• ISL32741E product page

3.3V

5V

3.3V

ISOLATION

BARRIER

100n

12

ISOLATION

BARRIER

100n

1

16

1

390R

220R

390R

220R

390R

VDD1

VDD2

A

VDD2

A

VDD1

R

3

4

5

6

12

3

4

5

6

R

RE

DE

RE

DE

13

10

13

10

B

D

ISODE

GND2

ISODE

GND2

D

GND1

1M

4.7n

1M

2, 8

9,15

2, 8

ISL32741E

Figure 1. Typical PROFIBUS Application

FN8944 Rev.2.00

Nov 30, 2017

Page 1 of 19

ISL32741E

1. Overview

1.1

Typical Operating Circuit

3.3V

5V

3.3V

ISOLATION

BARRIER

ISOLATION

BARRIER

100n

1

16

1

VDD1

VDD2

VDD1

R

FS

390R

3

4

6

R

3

4

6

A

B

12

A

B

RE

D

RE

R

220R

R

T

220R

T

Z

= 150R ±10%

0

D

13

5

DE

ISODE 10

10 ISODE

DE

5

R

FS

390R

GND1

2, 8

GND2

9,15

GND2

GND1

2, 8

9,15

ISL32741E

Figure 2. Typical Operating Circuit

1.2

Ordering Information

Part Number

(Notes 1, 2, 3)

Temp. Range

(°C)

Package

(RoHS Compliant)

Part Marking

32741EIBZ

Pkg. Dwg. #

M16.3A

ISL32741EIBZ

ISL32741EFBZ

ISL32741EVAL1Z

Notes:

-40 to +85

16 Ld SOICW

32741EFBZ

-40 to +125

Evaluation board

1. Add “-T” suffix for 1k unit or “-T7A” suffix for 250 unit tape and reel options. Refer to TB347 for details on reel specifications.

2. Intersil Pb-free plus anneal products employ special Pb-free material sets; molding compounds/die attach materials and 100%

matte tin plate termination finish, which are RoHS compliant and compatible with both SnPb and Pb-free soldering operations.

Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements

of IPC/JEDEC J STD-020.

3. For Moisture Sensitivity Level (MSL), see the product information page for ISL32741E. For more information on MSL, see

TB363.

Table 1. Key Differences Between Family of Parts

V

(V)

V

(V)

Data Rate

(Mbps)

Isolation Voltage

(kV

DD1

DD2

Part Number

ISL32704E

Full/Half Duplex

)

RMS

Half

Full

Half

3.0 – 5.5

4.5 – 5.5

4

2.5

6

ISL32705E

ISL32740E

ISL32741E

40

FN8944 Rev.2.00

Nov 30, 2017

Page 2 of 19

ISL32741E

1. Overview

1.3

Pin Configuration

ISL32741E

(16 Ld SOICW)

Top View

VDD1

GND1

R

1

2

3

4

5

6

7

8

16 VDD2

15 GND2

14 NC

RE

13 B

DE

12 A

D

11 NC

NC

10 ISODE

GND1

9 GND2

1.4

Truth Tables

Transmitting

Inputs

Outputs

RE

X

DE

1

D

1

ISODE

B

0

A

1

0

1

X

1

0

1

0

X

High-Z

High-Z*

High-Z

High-Z*

1

0

Receiving

Inputs

Output

RE

0

DE

A-B

≥ -0.05V

RO

0

1

0

V

1

AB

0

-0.05V > V >-0.2V

Undetermined

AB

0

V

≤ -0.2V

0

AB

0

Inputs Open/Shorted

1

X

High-Z

High-Z*

1

Note: *Transceiver shutdown mode

FN8944 Rev.2.00

Nov 30, 2017

Page 3 of 19

ISL32741E

1. Overview

1.5

Pin Descriptions

Number

Name

Function

1

2, 8

3

VDD1 Input power supply.

GND1 Input power supply ground return. Pin 2 is internally connected to Pin 8.

R

Receiver output: If A-B ≥-50mV, R is high; If A-B ≤-200mV, R is low; R = High if A and B are unconnected (floating)

or shorted, or connected to a terminated bus that is not driven.

4

5

6

RE

DE

D

Receiver output enable. R is enabled when RE is low; R is high impedance when RE is high. If the Rx enable

function is not required, connect RE directly to GND1.

Driver output enable. The driver outputs, A and B, are enabled by bringing DE high. They are high impedance

when DE is low. If the Tx enable function isn’t required, connect DE to VDD1 through a 1kΩ or greater resistor.

Driver input. A low on D forces output A low and output B high. Similarly, a high on D forces output A high and

output B low.

7, 11, 14

9, 15

10

NC

No internal connection.

GND2 Output power supply ground return. Pin 9 is internally connected to Pin 15.

ISODE Isolated DE output for use in PROFIBUS applications where the state of the isolated drive enable node needs to

be monitored.

12

13

16

A

±15kV IEC61000 ESD protected RS-485/RS422 level, noninverting receiver input if DE = 0 and noninverting

driver output if DE = 1.

B

±15kV IEC61000 ESD protected RS-485/RS422 level, inverting receiver input if DE = 0 and inverting driver

output if DE = 1.

VDD2 Output power supply.

FN8944 Rev.2.00

Nov 30, 2017

Page 4 of 19

ISL32741E

2. Specifications

2.1

Absolute Maximum Ratings

Parameter (Note 4)

Minimum

-0.5

Maximum

Unit

Supply Voltages (Note 7)

VDD1 to GND1

VDD2 to GND2

Input Voltages D, DE, RE

Input/Output Voltages

A, B

+7

7

V

-0.5

VDD1 + 0.5

-9

+13

V

R

-0.5

VDD1 + 1

Short-Circuit Duration A, B

ESD Rating

Continuous

See “Electrical Specifications” table on page 7

Note:

4. Absolute Maximum specifications mean the device will not be damaged if operated under these conditions. It does not

guarantee performance.

CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may

adversely impact product reliability and result in failures not covered by warranty.

2.2

Thermal Information

Thermal Resistance (Typical)



(°C/W)



(°C/W)

JC

JA

16 Ld SOICW Package (Notes 5, 6)

Notes:

43

20

5.  is measured in free air with the component soldered to a double-sided board.

JA

6. For  , the “case temp” location is the center of the package top side.

JC

Parameter

Maximum Junction Temperature (Plastic Package)

Maximum Storage Temperature Range

Maximum Power Dissipation

Minimum

-55

Maximum

Unit

°C

+150

800

-55

°C

mW

Pb-Free Reflow Profile

see TB493

2.3

Recommended Operation Conditions

Parameter

Minimum

Maximum

Unit

Supply Voltages

V

3.0

4.5

5.5

V

DD1

DD2

High-Level Digital Input Voltage, V

IH

V

= 3.3V

= 5.0V

2.4

3.0

0

V

DD1

Low-Level Digital Input Voltage, V

0.8

12

IL

Differential Input Voltage, V (Note 8)

ID

-7

FN8944 Rev.2.00

Nov 30, 2017

Page 5 of 19

ISL32741E

2. Specifications

Parameter

High-Level Output Current (Driver), I

Minimum

Maximum

Unit

mA

°C

60

8

OH

High-Level Digital Output Current (Receiver), I

OH

Low-Level Output Current (Driver), I

-60

OL

Low-Level Digital Output Current (Receiver), I

Junction Temperature, T

-8

OL

-40

+110

+85

J

Ambient Operating Temperature, T

ISL32741EIBZ

ISL32741EFBZ

°C

A

+125

DC Stable

°C

Digital Input Signal Rise and Fall Times, t , t

IR IF

2.4

Electrical Specifications

Test conditions: T

min

to T

, V

= V

= 4.5V to 5.5V; unless otherwise stated. (Note 7)

DD2

max DD1

Typ

(Note 11) Max Unit

Parameter

DC Characteristics

Driver Line Output Voltage (V , V )

Symbol

Test Conditions

Min

V

No load

-

V

A

B

O

DD2

(Note 7)

Driver Differential Output Voltage (Note 8)

V

-

V

OD1

OD2

OD3

V

R

= 54Ω

= 60Ω

2.1

1.9

2.8

2.7

L

DD2

-

Driver Differential Output Voltage

(Notes 8, 12)

L

Change in Magnitude of Differential Output

Voltage (Note 13)

V

R

= 54Ω or 100Ω

-

0.01

0.20

V

OD

L

Driver Common-Mode Output Voltage

V

R

= 54Ω or 100Ω

-

3

V

OC

L

Change in Magnitude of Driver

V

0.01

0.20

OC

L

Common-Mode Output Voltage (Note 13)

Bus Input Current (A, B) (Notes 10, 14)

I

DE = 0V

V

= 12V

= -7V

-

220

µA

IN2

IN

-160

High-Level Input Current (DI, DE, RE)

Low-Level Input Current (DI, DE, RE)

Absolute Short-Circuit Output Current

Supply Current

I

V = 3.5V

-

10

-

IH

I

V = 0.4V

-10

IL

I

DE = V

, -7V ≤ V or V ≤ 12V

DD1

-

±250 mA

OS

A

B

I

V

= 5V

-

4

3

-

6

4

mA

mV

pF

V

DD1

= 3.3V

-

Positive-Going Input Threshold Voltage

Negative-Going Input Threshold Voltage

Receiver Input Hysteresis

V

-7V ≤ V

≤ 12V

-

-50

-

TH+

CM

V

-200

-

TH-

V

= 0V

CM

-

28

9

-

HYS

Differential Bus Input Capacitance

Receiver Output High Voltage

Receiver Output Low Voltage

High impedance Output Current

Receiver Input Resistance

C

12

-

D

V

I

= -20µA, V = -50mV

ID

V

- 0.2

CC

OH

O

V

= +20µA, V = -200mV

ID

-

-1

54

-

0.2

1

V

OL

I

0.4V ≤ V ≤ (V

- 0.5)

-

µA

kΩ

mA

OZ

O

DD2

R

-7V ≤ V

≤ 12V

80

5

-

IN

CM

Supply Current

I

DE = V

, no load

16

DD2

DD1

FN8944 Rev.2.00

Nov 30, 2017

Page 6 of 19

ISL32741E

2. Specifications

Test conditions: T

to T

, V

= V

= 4.5V to 5.5V; unless otherwise stated. (Note 7) (Continued)

DD2

min

max DD1

Typ

(Note 11) Max Unit

Parameter

ESD Performance

Symbol

Test Conditions

Min

RS-485 Bus Pins (A, B)

IEC61000-4-2, air-gap discharge to

GND2

-

±15

±8

-

kV

IEC61000-4-2, contact discharge to

GND2

Human Body Model (HBM) discharge to

GND2

±16.5

±2

All Pins (R, RE, D, DE)

Human Body Model (HBM) discharge to

GND1

Switching Characteristics

V

= 5V, V

= 5V

DD2

DD1

Data Rate

DR

R

= 54Ω, C = 50pF

40

-

Mbps

ns

L

Propagation Delay (Notes 8, 15)

Pulse Skew (Notes 8, 16)

t

V

= -1.5V to 1.5V, C = 15pF

20

1

30

5

PD

(P)

O

L

t

V

= -1.5V to 1.5V, C = 15pF

-

ns

SK

L

Skew Limit (Note 9)

t

(LIM)

R

= 54Ω, C = 50pF

L

-

2

10

30

-

ns

SK

L

Output Enable Time to High Level

Output Enable Time to Low Level

t

C

= 15pF

-

15

50

ns

PZH

L

t

-

ns

PZL

L

Output Disable Time from High Level

Output Disable Time from Low Level

Common-Mode Transient Immunity

t

-

ns

PHZ

L

t

-

ns

PLZ

L

CMTI

V

= 1500 V , t

DC TRANSIENT

= 25ns

30

kV/µs

CM

V

= 3.3V, V

= 5V

DD2

DD1

Data Rate

DR

R

= 54Ω, C = 50pF

40

-

Mbps

ns

L

Propagation Delay (Notes 8, 2)

Pulse Skew (Notes 8, 3)

t

V

= -1.5V to 1.5V, C = 15pF

25

2

35

5

PD

(P)

O

L

t

V

= -1.5V to 1.5V, C = 15pF

-

ns

SK

L

Skew Limit (Note 9)

t

(LIM)

R

= 54Ω, C = 50pF

L

-

4

10

30

-

ns

SK

L

Output Enable Time to High Level

Output Enable Time to Low Level

Output Disable Time from High Level

Output Disable Time from Low Level

Common-Mode Transient Immunity

t

C

= 15pF

-

17

50

ns

PZH

L

t

-

ns

PZL

L

t

-

ns

PHZ

L

t

-

ns

PLZ

L

CMTI

V

= 1500 V , t

DC TRANSIENT

= 25ns

30

kV/µs

CM

Notes: (apply to both driver and receiver sections)

7. All voltages on the isolator primary side are with respect to GND1, all line voltages and common-mode voltages on the isolator

secondary or bus side are with respect to GND2.

8. Differential I/O voltage is measured at the noninverting bus Terminal A with respect to the inverting Terminal B.

9. Skew limit is the maximum propagation delay difference between any two devices at +25°C.

10. The power-off measurement in ANSI Standard EIA/TIA-422-B applies to disabled outputs only and is not applied to combined

inputs and outputs.

11. All typical values are at V

, V

= 5V or V

= 3.3V and T = +25°C.

DD1 A

DD1 DD2

12. -7V < V

< 12V; 4.5 < V < 5.5V.

CM

and V

DD

are the changes in magnitude of V

13. V

and V

respectively, that occur when the input is changed from one

OD

OC

OD

logic state to the other.

14. This applies for both power-on and power-off; refer to ANSI standard RS-485 for the exact condition. The EIA/TIA-422 -B limit

does not apply for a combined driver and receiver terminal.

15. Includes 10ns read enable time. Maximum propagation delay is 25ns after read assertion.

16. Pulse skew is defined as |t

- t | of each channel.

PLH PHL

FN8944 Rev.2.00

Nov 30, 2017

Page 7 of 19

ISL32741E

2. Specifications

2.5

Insulation Specifications

Parameter

Symbol

Test Conditions

Min

Typ

8.3

13

Max

Unit

mm

µm

Ω

Creepage Distance (External)

Total Barrier Thickness (Internal)

Barrier Resistance

Per IEC 60601

8.03

-

14

R

C

500V

-

>10

IO

Barrier Capacitance

f = 1MHz

-

7

pF

Leakage Current

240V

, 60Hz

-

0.2

µA

RMS

Comparative Tracking Index

CTI

Per IEC 60112

≥600

1000

1500

-

V

High Voltage Endurance (Maximum

Barrier Voltage for Indefinite Life)

V

At maximum operating temperature

-

IO

V

DC

Barrier Life

100°C, 1000V

energy

, 60% CL activation

44000

Years

RMS

2.6

Magnetic Field Immunity

Parameter (Note 17)

= 5V, V = 5V

Symbol

Test Conditions

Min

Typ

Max

Unit

V

DD1

DD2

Power Frequency Magnetic Immunity

Pulse Magnetic Field Immunity

H

50Hz/60Hz

t = 8µs

P

-

3500

4500

2.5

-

A/m

PF

H

PM

Damped Oscillatory Magnetic Field

Cross-Axis Immunity Multiplier (Note 18)

H

0.1Hz to 1MHz

OSC

K

X

V

= 3.3V, V

= 5V

DD2

DD1

Power Frequency Magnetic Immunity

Pulse Magnetic Field Immunity

Damped Oscillatory Magnetic Field

Cross-Axis Immunity Multiplier (Note 18)

Notes:

H

50Hz/60Hz

-

1500

2000

2.5

-

A/m

PF

H

t = 8µs

P

PM

H

0.1Hz to1MHz

OSC

K

X

17. The relevant test and measurement methods are given in the “Electromagnetic Compatibility” on page 10.

18. External magnetic field immunity is improved by this factor if the field direction is “end-to-end” rather than “pin-to-pin”

(See “Electromagnetic Compatibility” on page 10).

FN8944 Rev.2.00

Nov 30, 2017

Page 8 of 19

ISL32741E

3. Safety and Approvals

3.1

VDE V 0884-10

Reinforced Isolation; VDE File Number 5022321-4880-0002/232903

• Working voltage (V ) 1000V (1415V ); Reinforced insulation, Pollution degree 2

IORM PK

RMS

) 12.8kV

• Isolation voltage (V ) 6000V

ISO

• Surge Immunity (V

• Surge rating 8kV

IOSM

PK

• Transient overvoltage (V

) 6000V

IOTM

PK

• Each part tested at 2387V for 1s, 5pC partial discharge limit

PK

• Samples tested at 6000V for 60s, then 2122V for 10s with 5pC partial discharge limit

PK

Symbol

Safety-Limiting Values

Value

+180

270

Unit

°C

T

P

Safety Rating Ambient Temperature

Safety Rating Power (+180°C)

S

mW

mA

S

I

Supply Current Safety Rating (total of supplies)

54

S

3.2

UL 1577

Component Recognition Program File Number E483309

• 6kV rating

• Each part tested at 7.2kV

RMS

(10.2kV ) for 1s

PK

• Each lot samples tested at 6000V

(8485V ) for 60s

PK

RMS

FN8944 Rev.2.00

Nov 30, 2017

Page 9 of 19

ISL32741E

4. Electromagnetic Compatibility

The ISL32741E is fully compliant with generic EMC standards EN50081, EN50082-1, and the umbrella line-voltage

standard for Information Technology Equipment (ITE) EN61000. The isolator’s Wheatstone bridge configuration and

differential magnetic field signaling ensure excellent EMC performance against all relevant standards. Compliance

tests have been conducted in the following categories:

Table 2. Compliance Test Categories

EN50081-1

EN50082-2

EN50204

Residential, Commercial, and

Light Industrial:

Industrial Environment

EN61000-4-2 (ESD)

Radiated field from digital

telephones

Methods EN55022, EN55014

EN61000-4-3 (Electromagnetic Field Immunity)

EN61000-4-4 (EFT)

EN61000-4-6 (RFI Immunity)

EN61000-4-8 (Power Frequency Magnetic Field immunity)

EN61000-4-9 (Pulsed Magnetic Field)

EN61000-4-10 (Damped Oscillatory Magnetic Field)

Immunity to external magnetic fields is even higher if the field direction is

“end-to-end” rather than “pin-to-pin” as shown on the right.

FN8944 Rev.2.00

Nov 30, 2017

Page 10 of 19

ISL32741E

5. Application Information

The ISL32741E is a 6kV reinforced isolated PROFIBUS transceiver specifically designed for PROFIBUS-DP

applications.

5.1

PROFIBUS

This transceiver uses a differential input receiver for maximum noise immunity and common-mode rejection.

PROFIBUS (Process Field Bus) is specified in IEC61158 as a standard for field bus communication in automation

technology. Two versions of PROFIBUS exist: PROFIBUS - PA for Process Automation and PROFIBUS-DP for

Decentralized Peripherals. The most commonly used, PROFIBUS-DP, is a protocol for deterministic

communication between PROFIBUS masters and their remote I/O slaves.

While the physical layer of PROFIBUS-DP is based on RS-485 with its differential signaling scheme, significant

differences between the two physical layers exist with regard to cable type, bus termination, and minimum bus

voltage, to name just a few parameters.

Table 3. Main Differences Between RS-485 and PROFIBUS-DP

Parameter

RS-485

Unshielded twisted pair

120Ω

PROFIBUS-DP

Shielded twisted pair

150Ω

Cable Type

Characteristic Impedance

Minimum Driver Output Voltage

Transceiver Input Capacitance

External Fail-Safe Biasing

1.5V

2.1V

10 to 15pF

10pF

Customer configurable

Always at both cable ends

(none, at single or both cable ends)

Resistor Values

Customer configurable

Fixed

5.2

Galvanic Isolation

To enable PROFIBUS transceivers operating over a wider common-mode voltage range than specified in RS-485

(7V to +12V), modern transceiver designs incorporate galvanic digital isolators with the transceiver circuitry. Here

the ISL32741E uses a Giant Magnetoresistance (GMR) isolation. Figure 3 shows the principle operation of a single

channel GMR isolator.

EXTERNAL B-FIELD

V

DD2

INTERNAL

B-FIELD

GMR1

GMR2

IN

OUT

GMR3 GMR4

GND2

Figure 3. Single Channel GMR Isolator

The input signal is buffered and drives a primary coil, which creates a magnetic field that changes the resistance of

the GMR resistors 1 to 4. GMR1 to GMR4 form a Wheatstone bridge to create a bridge output voltage that reacts

only to magnetic field changes from the primary coil. Large external magnetic fields however, are treated as

common-mode fields, and are therefore suppressed by the bridge configuration. The bridge output is fed into a

comparator whose output signal is identical in phase and shape to the input signal.

FN8944 Rev.2.00

Nov 30, 2017

Page 11 of 19

ISL32741E

5. Application Information

5.3

GMR Resistor in Detail

Figure 4 shows a GMR resistor consisting of ferromagnetic alloy layers B1 and B2 sandwiched around an ultra

thin, nonmagnetic conducting middle layer A, typically copper. The GMR structure is designed so that in the

absence of a magnetic field, the magnetic moments in B1 and B2 face opposite directions, thus causing heavy

electron scattering across layer A, which increases its resistance for current C drastically. When a magnetic field D

is applied, the magnetic moments in B1 and B2 are aligned and electron scattering is reduced. This lowers the

resistance of layer A and current C increases.

HIGH

LOW

RESISTANCE

B1

A

B1

A

C

B2

D

APPLIED

MAGNETIC FIELD

Figure 4. Multilayer GMR Resistor

5.4

Low Emissions

Because GMR isolators do not use fancy encoding schemes, such as RF carriers or high-frequency clocks, and do

not include power transfer coils or transformers, their radiated emission spectrum is practically undetectable.

60

50

40

30

20

10

0

FCC-B < 1GHz 3m

EN55022 < 1GHz 3m

LABORATORY NOISE FLOOR

QP-MEASUREMENTS

10MHz

100MHz

1GHz

Figure 5. Undetectable Emissions of GMR Isolators

5.5

Low EMI Susceptibility

Because GMR isolators have no pulse trains or carriers to interfere with, they also have very low EMI susceptibility.

For the list of compliance tests conducted on GMR isolators, refer to “Electromagnetic Compatibility” on page 10.

5.6

Receiver (Rx) Features

This transceiver uses a differential input receiver for maximum noise immunity and common-mode rejection. Input

sensitivity is ±200mV, as required by the RS-422 and RS-485 specifications. Receiver inputs function with

common-mode voltages as great as 7V outside the power supplies (for example, +12V and -7V), making them ideal

for long networks, or industrial environments, where induced voltages are a realistic concern.

The receiver input resistance of 54kΩ surpasses the RS-422 specification of 4kΩ and is about five times the

RS-485 “Unit Load” (UL) requirement of 12kΩ minimum. Thus, the ISL32741E is known as a “one-fifth UL”

transceiver, and there can be up to 160 devices on the RS-485 bus while still complying with the RS-485 loading

specification.

FN8944 Rev.2.00

Nov 30, 2017

Page 12 of 19

ISL32741E

5. Application Information

The receiver is a “full fail-safe” version that ensures a high-level receiver output if the receiver inputs are

unconnected (floating), shorted together, or connected to a terminated bus with all the transmitters disabled

(terminated/undriven).

Rx outputs deliver large low state currents (typically >30mA) at V = 1V.

OL

Receivers easily meet the 40Mbps data rate supported by the driver, and the receiver output is tri-statable using the

active low RE input.

5.7

Driver (Tx) Features

The RS-485/RS-422 driver is a differential output device that delivers at least 2.1V across a 54Ω load

(RS-485/PROFIBUS), and at least 2.6V across a 100Ω load (RS-422) even with V = 4.5V. The drivers feature

CC

low propagation delay skew to maximize bit width and to minimize EMI.

Outputs of the drivers are not slew rate limited, so faster output transition times allow data rates of at least 40Mbps.

Driver outputs are tri-statable through the active high DE input.

5.7.1

High V

Improves Noise Immunity and Flexibility

OD

The ISL32741E driver design delivers larger differential output voltages (V ) than the RS-485 standard

OD

requires, or than most RS-485 transmitters can deliver. The minimum ±2.1V V

ensures at least ±600mV

OD

transmitters.

more noise immunity than networks built using standard 1.5V V

OD

Another advantage of the large V

is the ability to drive more than two bus terminations, which allows for

OD

using the ISL32741E in “star” and other multi-terminated, “nonstandard” network topologies.

5.8

Built-In Driver Overload Protection

As stated previously, the RS-485 specification requires that drivers survive worst case bus contentions undamaged.

These transmitters meet this requirement through driver output short-circuit current limits, and on-chip thermal

shutdown circuitry.

The driver output stages incorporate short-circuit current limiting circuitry, which ensures that the output current

never exceeds the RS-485 specification, even at the common-mode voltage range extremes. In the event of a major

short-circuit condition, the device also includes a thermal shutdown feature that disables the drivers whenever the

die temperature becomes excessive. This eliminates the power dissipation, allowing the die to cool. The drivers

automatically re-enable after the die temperature drops about 15°C. If the contention persists, the thermal

shutdown/re-enable cycle repeats until the fault is cleared. Receivers stay operational during thermal shutdown.

5.9

Dynamic Power Consumption

The isolator within the ISL32741E achieves its low power consumption from the way it transmits data across the

barrier. By detecting the edge transitions of the input logic signal and converting these to narrow current pulses, a

magnetic field is created around the GMR Wheatstone bridge. Depending on the direction of the magnetic field, the

bridge causes the output comparator to switch following the input signal. Because the current pulses are narrow,

about 2.5ns, the power consumption is independent of the mark-to-space ratio and solely depends on frequency.

Table 4. Supply Current Increase with Data Rate

Data Rate

(Mbps)

I

DD2

DD1

(mA)

0.15

1.5

3

(mA)

0.15

1.5

3

1

10

20

40

6

FN8944 Rev.2.00

Nov 30, 2017

Page 13 of 19

ISL32741E

5. Application Information

5.10 Power Supply Decoupling

Both supplies, V

and V

, must be bypassed with 100nF ceramic capacitors. These should be placed as close

DD1

DD2

as possible to the supply pins for proper operation.

5.11 DC Correctness

The ISL32741E incorporates a patented refresh circuit to maintain the correct output state with respect to data input.

At power-up, the bus outputs follow the “Truth Tables” on page 3. The DE input should be held low during power-up

to prevent false drive data pulses on the bus.

5.12 Data Rate, Cables, and Terminations

Twisted pair is the cable of choice for RS-485, RS-422, and PROFIBUS networks. Twisted pair cables tend to pick

up noise and other electromagnetically induced voltages as common-mode signals, which are effectively rejected

by the differential receivers in these ICs.

According to guidelines in the RS-422 and PROFIBUS specifications, networks operating at data rates in excess of

3Mbps should be limited to cable lengths of 100m (328 ft) or less and the PROFIBUS specification recommends

that the more expensive “Type A” (22AWG) cable be used. The ISL32741E’s large differential output swing, fast

transition times, and high drive-current output stages allow operation even at 40Mbps over standard “CAT 5”

cables in excess of 100m (328 ft).

The ISL324741E can also be used at slower data rates over longer cables, but there are some limitations. The Rx is

optimized for high-speed operation, so its output may glitch if the Rx input differential transition times are too

slow. Keeping the transition times below 500ns, (which equates to the Tx driving a 1000’ (305m) CAT 5 cable)

yields excellent performance across the full operating temperature range.

To minimize reflections, proper termination is imperative when using this high data rate transceiver. In

point-to-point, or point-to-multipoint (single driver on bus) networks, the main cable should be terminated in its

characteristic impedance (typically 100Ω for “CAT 5”, 120Ω for RS-485, and 150Ω for “Type A”) at the end

farthest from the driver. In multireceiver applications, stubs connecting receivers to the main cable should be kept

as short as possible. Multipoint (multidriver) systems require that the main cable be terminated in its characteristic

impedance at both ends. Stubs connecting transceivers to the main cable should be kept as short as possible.

PROFIBUS specifies line termination with fail-safe biasing networks of fixed resistor values at both cable ends.

V_S

R_B

R_T

R_B

R_T

R_B

390R

220R

390R

220R

390R

Figure 6. Line Termination for PROFIBUS-DP

For isolated data links meeting the requirements of EIA-485, the resistor values for the fail-safe biasing network

can be calculated using (EQ. 1) through (EQ. 4).

For data links longer than 100m (330ft) apply fail-safe biasing at both cable ends to compensate for the attenuation

of the bus fail-safe voltage caused by the voltage divider action of the cable’s DC resistance and the remote

fail-safe biasing network. Use (EQ. 1) to calculate the bias resistors, R , and (EQ. 2) to determine the termination

B

resistors, R .

T

V

Z

0

2

S

----------- ------

R





(EQ. 1)

B

V

AB

FN8944 Rev.2.00

Nov 30, 2017

Page 14 of 19

ISL32741E

5. Application Information

2R  Z

B

0

R

= ------------------------

(EQ. 2)

T

2R – Z

B

0

where:

• R is the value of the biasing resistors.

B

• R is the value of the termination resistors.

T

• V is the minimum transceiver supply voltage.

S

• V is the minimum bus voltage during bus idling.

AB

• Z is the characteristic cable impedance of 120Ω.

0

V_S1

V_S2

R_B

R_T

R_B

R_T

R_B

1.09k

127R

1.09k

127R

1.09k

GND2

GND1

Figure 7. Dual Fail-Safe Biasing for Long Data Links

For data links shorter than 100m, use a single fail-safe biasing network. Match the termination resistor value at the

cable end without fail-safe biasing with the characteristic cable impedance: R = Z . Then calculate R using

T1

0

B

(EQ. 3) and R using (EQ. 4).

T2

V

Z

0

4

S

----------- ------

R





(EQ. 3)

(EQ. 4)

B

V

AB

2R  Z

B

0

R

= ------------------------

T2

2R – Z

B

0

V

S

R

542R

135R

542R

B

R

120R

R

T1

T2

R

B

Figure 8. Single Fail-Safe Biasing for Short Data Links

Note, the resistor values in Figures 7 and 8 have been calculated for V = 4.5V, V = 0.25V, and Z = 120Ω.

S

AB

0

FN8944 Rev.2.00

Nov 30, 2017

Page 15 of 19

ISL32741E

5. Application Information

5.13 Transient Protection

Protecting the ISL32741E against transients exceeding the device’s transient immunity requires the addition of an

external TVS. For this purpose, Semtech’s RClamp0512TQ was chosen due to its high transient protection levels,

low junction capacitance, and small form factor.

Table 5. RCLAMP0512 TVS Features

Parameter

Symbol

Value

±30

±4

Unit

kV

ESD (IEC61000-4-2)

Air

V

ESD

Contact

kV

EFT (IEC61000-4-4)

Surge (IEC61000-4-5)

Junction Capacitance

Form Factor

V

kV

EFT

V

±1.3

3

kV

SURGE

C

pF

J

-

1 x 0.6

mm

The TVS is implemented between the bus lines and isolated ground (GND2).

Because transient voltages on the bus lines are referenced to Earth potential, also known as Protective Earth (PE), a

high-voltage capacitor (C ) is inserted between GND2 and PE, providing a low-impedance path for

HV

high-frequency transients.

Note that the connection from the PE point on the isolated side to the PE point on the non-isolated side (Earth) is

usually made using the metal chassis of the equipment, or through a short, thick wire of low-inductance.

A high-voltage resistor (R ) is added in parallel to C

HV HV

to prevent the build-up of static charges on floating

grounds (GND2) and cable shields (typically used in PROFIBUS). The bill of materials for the circuit in Figure 9 is

listed in Table 6.

V

S-ISO

V

S

12

13

A

MCU/

UART

ISL32741E

B

1

2

Shield

TVS

3

GND

PE

C

HV

R

HV

PE

Non-isolated Ground

Isolated Ground, Floating RS-485 Common

Protective Earth Ground, Equipment Safety Ground

Figure 9. Transient Protection for ISL32741E

Table 6. BOM for Circuit in Figure 9

Name

Function

Order No.

RCLAMP0512TQ

Vendor

TVS

170W (8, 20µs) 2-LINE PROTECTOR

4.7nF, 2kV, 10% CAPACITOR

1MΩ, 2kV, 5% RESISTOR

Semtech

Novacap

C

R

1812B472K202NT

HVC12061M0JT3

HV

TT-Electronics

FN8944 Rev.2.00

Nov 30, 2017

Page 16 of 19

ISL32741E

6. Revision History

Rev.

2.00

1.00

Date

Description

Updated certification file numbers for VDE and UL.

Nov 30, 2017

Aug 24, 2017

Updated Table 1 on page 2.

Updated receiving truth table.

0.00

Jun 28, 2017

Initial release

FN8944 Rev.2.00

Nov 30, 2017

Page 17 of 19

ISL32741E

7. Package Outline Drawing

For the most recent package outline drawing, see M16.3A.

7. Package Outline Drawing

M16.3A

16 LEAD WIDE BODY SMALL OUTLINE PLASTIC PACKAGE (SOICW)

Rev 1, 6/17

1

3

10.08

10.49

0.3

0.5

SEE DETAIL "X"

16

9

0.18

0.25

7.42

7.59

10.00

10.64

6.60

7.11

PIN #1

I.D. MARK

2

3

0.85

1.10

1

8

1.24

1.30

0.2

0.3

TOP VIEW

END VIEW

0.05

2.34

2.67

H

C

2.0

2.5

GAUGE

PLANE

SEATING

PLANE

0.25

0.1

0.3

0.5

5

0.1 MIN

0.40

0.10

C

0° TO 8°

0.3 MAX

1.30

0.1 M

C

B A

SIDE VIEW

DETAIL X

(1.7)

NOTES:

19. Dimension does not include mold flash, protrusions, or gate burrs.

Mold flash, protrusions, or gate burrs shall not exceed 0.15 per side.

20. Dimension does not include interlead flash or protrusion. Interlead

flash or protrusion shall not exceed 0.25 per side.

(9.75)

21. Dimensions are measured at datum plane H.

22. Dimensioning and tolerancing per ASME Y14.5M-1994.

23. Dimension does not include dambar protrusion.

24. Dimension in ( ) are for reference only.

25. Pin spacing is a BASIC dimension; tolerances do not accumulate.

26. Dimensions are in mm.

(0.51)

(1.27)

TYPICAL RECOMMENDED LAND PATTERN

FN8944 Rev.2.00

Nov 30, 2017

Page 18 of 19

ISL32741E

8. About Intersil

Intersil Corporation is a leading provider of innovative power management and precision analog solutions. The

company's products address some of the largest markets within the industrial and infrastructure, mobile computing and

high-end consumer markets.

For the most updated datasheet, application notes, related documentation and related parts, please see the respective

product information page found at www.intersil.com.

For a listing of definitions and abbreviations of common terms used in our documents, visit:

www.intersil.com/glossary.

You can report errors or suggestions for improving this datasheet by visiting www.intersil.com/ask.

Reliability reports are also available from our website at www.intersil.com/support.

All trademarks and registered trademarks are the property of their respective owners.

For additional products, see www.intersil.com/en/products.html

Intersil products are manufactured, assembled and tested utilizing ISO9001 quality systems as noted

in the quality certifications found at www.intersil.com/en/support/qualandreliability.html

Intersil products are sold by description only. Intersil may modify the circuit design and/or specifications of products at any time without notice,

provided that such modification does not, in Intersil's sole judgment, affect the form, fit or function of the product. Accordingly, the reader is cautioned

to verify that datasheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no

responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result

from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.

For information regarding Intersil Corporation and its products, see www.intersil.com

FN8944 Rev.2.00

Nov 30, 2017

Page 19 of 19


型号：	ISL32741EVAL1Z
厂家：	RENESAS TECHNOLOGY CORP
描述：	PROFIBUS Compliant 6kV VDE-Reinforced Isolated RS-485 Transceiver
文件：	总19页 (文件大小：898K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

ISL32741EVAL1Z [RENESAS]

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