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PROTECTION PRODUCTS

SMDA05C-8 THRU SMDA24C-8

Circuit Diagram

Connection Diagram

Device Connection for Protection of Eight Data Lines

The SMDAxxC-8 is designed to protect up to 8 data or

I/O lines. They are bidirectional devices and may be

used on lines where the signal polarities are above and

below ground.

The SMDAxxC-8 TVS arrays employ a monolithic struc-

ture. Therefore, the working voltage (V

down voltage (V

tial voltage between any two data line pins. For ex-

ample, the SMDA24C-8 is designed for a maximum

voltage excursion of +/-12V between any two data

lines.

The device is connected as follows:

l

Pins 2, 3, 5, 6, 9, 10, 12 and 13 are connected to

the lines that are to be protected. Pins 1, 7, 8,

and 14 are connected to ground. The ground

connections should be made directly to the ground

plane for best results. The path length is kept as

short as possible to reduce the effects of parasitic

inductance in the board traces. Pins 4 and 11 are

not connected.

Circuit Board Layout Recommendations for Suppres-

sion of ESD.

Good circuit board layout is critical for the suppression

of ESD induced transients. The following guidelines are

recommended:

l

Place the TVS near the input terminals or connec-

tors to restrict transient coupling.

l

Minimize the path length between the TVS and the

protected line.

l

Minimize all conductive loops including power and

ground loops.

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The ESD transient return path to ground should be

kept as short as possible.

l

Never run critical signals near board edges.

l

Use ground planes whenever possible.

GND

GND

I/O 1

I/O 2

N.C.

I/O 3

I/O 4

GND

N.C.

GND

I/O 5

I/O 6

I/O 7

I/O 8

1

2

3

4

5

6

7

8

9

10

11

12

13

14

Applications Information