PLC496

4

05109.R7 2/07

www.protekdevices.com

CIRCUIT BOARD LAYOUT RECOMMENDATIONS

Circuit board layout is critical for Electromagnetic

Compatibility (EMC) protection. The following guidelines

are recommended:

✔

The protection device should be placed near the

input terminals or connectors, the device will divert

the transient current immediately before it can be

coupled into the nearby traces.

✔

The path length between the TVS device and the

protected line should be minimized.

✔

All conductive loops including power and ground

loops should be minimized.

✔

The transient current return path to ground should

be kept as short as possible to reduce parasitic

inductance.

✔

Ground planes should be used whenever possible.

For multilayer PCBs, use ground vias.

The PLC496 is an ultra low capacitance, bidirectional array that is designed to protect I/O or high speed data lines from the damaging effects of ESD

or EFT. This product has a surge capability of 500 Watts P

DIFFERENTIAL-MODE CONFIGURATION (Figure 1)

The PLC496 is designed to protect one bidirectional line where the normal signal

voltage is both positive and negative. Figure 1 shows a typical differential-mode

line to line) I/O port protection circuit application.

Circuit connectivity is as follows:

✔ Pins 1, 4 5 and 8 are connected to the data lines

✔ Pins 2, 3, 7 and 6 are not connected.

COMMON-MODE CONFIGURATION (Figure 2)

The PLC496 can provide protection for sensor circuit applications. Figure 2, is a

typical common-mode (line to ground) sensor circuit application.

Circuit connectivity is as follows:

✔ Pins 1 and 8 connected to the dataline

✔ Pins 4 and 5 connected to ground

✔ Pins 2, 3, 6, and 7 are not connected

LINE 2 IN

Figure 1. Typical Differential Mode I/O Port Protection

1

2

3

8

4

7

6

5

LINE 1

OUT

LINE 1 IN

LINE 2

OUT

NC

NC

NC

NC

18

2

3

4

7

6

5

18

2

3

4

7

6

5

Figure 2. Typical Common Mode Sensor Protection Circuit

SENSOR

CIRCUITRY

NC

NC

NC

NC

NC

NC

NC

NC

APPLICATION NOTE