GND1

GND2

INB

OUTB

16

15

14

13

12

11

10

9

1

2

3

4

5

6

7

8

GND2

NC

NC

OUTA

GND1

OUTB

VCC1

INA

VCC2

INB

GND1

NC

NC

GND2

NC

NC

GND1

GND2

GND2

VCC2

0.1 P F

VCC1

GND1

0.1 P F

ISO7820

16

15

14

13

12

11

10

9

1

2

3

4

5

6

7

8

GND2

NC

NC

INA

GND1

OUTB

VCC1

OUTA

VCC2

INB

GND1

NC

NC

GND2

NC

NC

OUTA

INA

22

ISO7820, ISO7820F

SLLSEP0A – JULY 2015 – REVISED MARCH 2016

www.ti.com

Product Folder Links: ISO7820 ISO7820F

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Copyright © 2015–2016, Texas Instruments Incorporated

9.2.2 Detailed Design Procedure

Unlike optocouplers, which need external components to improve performance, provide bias, or limit current,

ISO7820 only needs two external bypass capacitors to operate.

Figure 17. Typical ISO7820 Circuit Hook-up

9.2.2.1 Electromagnetic Compatibility (EMC) Considerations

Many applications in harsh industrial environment are sensitive to disturbances such as electrostatic discharge

(ESD), electrical fast transient (EFT), surge and electromagnetic emissions. These electromagnetic disturbances

are regulated by international standards such as IEC 61000-4-x and CISPR 22. Although system-level

performance and reliability depends, to a large extent, on the application board design and layout, the ISO7820

incorporate many chip-level design improvements for overall system robustness. Some of these improvements

include:

•

Robust ESD protection for input and output signal pins and inter-chip bond pads.

•

Low-resistance connectivity of ESD cells to supply and ground pins.

•

Enhanced performance of high voltage isolation capacitor for better tolerance of ESD, EFT and surge events.

•

Bigger on-chip decoupling capacitors to bypass undesirable high energy signals through a low impedance

path.

•

PMOS and NMOS devices isolated from each other by using guard rings to avoid triggering of parasitic

SCRs.

•

Reduced common mode currents across the isolation barrier by ensuring purely differential internal operation.