14

13

INA

OUTD

3

4

5

6

0.1 F

EN1

EN2

7

10

INB

12

11

OUTC

IND

IN

C

DVDD

DGND

2

GAIN1

24

25

26

GAIN0

SPEED

PWDN

AIN3+

AIN3±

AIN4+

A0

A1

AIN1+

AIN1±

AIN2+

SCLK

DOUT

REF+

REF±

AIN4±

1

VCC1

16

VCC2

2, 8

9, 15

GND1

GND2

23

20

19

28

8

7

27

0.1 F

P3.1

P3.0

CLK

SOMI

13

11

12

14

4

2

MSP430F2132

DVss

DVcc

0.1 F

14

13

OUTD

3

4

5

6

0.1 F

NC

EN

7

10

12

11

OUTC

IND

IN

C

1

VCC1

16

VCC2

2, 8

9, 15

GND1

GND2

0.1 F

ISO7840

ISO7841

5 VISO

5 VISO

3.3 V

3.3 V

P3.7

P3.6

18

17

3.3 V

22

AVDD

AGND

21

5 VISO

0.1 F

AIN2±

13

14

17

16

15

11

12

18

INA

INB

OUTB

OUTA

OUTA

OUTB

1

0.1 F

0.1 F

5 VISO

5 VISO

Thermo

couple

Current

shunt

RTD

Bridge

XOUT

XIN

5

6

P3.4

15

P3.5

16

ADS1234

Isolation

Barrier

Copyright © 2016, Texas Instruments Incorporated

21

ISO7840, ISO7840F

www.ti.com

SLLSEN2B – JULY 2015 – REVISED APRIL 2016

Product Folder Links: ISO7840 ISO7840F

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Copyright © 2015–2016, Texas Instruments Incorporated

9 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component

specification, and TI does not warrant its accuracy or completeness. TI’s customers are

responsible for determining suitability of components for their purposes. Customers should

validate and test their design implementation to confirm system functionality.

9.1 Application Information

The ISO7840 device is a high-performance, quad-channel digital isolator with a 5.7-kVRMS isolation voltage. The

device comes with enable pins on each side that can be used to put the respective outputs in high impedance for

multi-master driving applications and reduce power consumption. The ISO7840 device uses single-ended

CMOS-logic switching technology. The supply voltage range is from 2.25 V to 5.5 V for both supplies, VCC1 and

VCC2. When designing with digital isolators, keep in mind that because of the single-ended design structure,

digital isolators do not conform to any specific interface standard and are only intended for isolating single-ended

CMOS or TTL digital signal lines. The isolator is typically placed between the data controller (that is, μC or

UART), and a data converter or a line transceiver, regardless of the interface type or standard.

9.2 Typical Application

Figure 18. Isolated Data Acquisition System for Process Control