Application Design Center - LCD TV

Circuit Protection of VGA Port

Solutions

• V0402MHS03
• SP724AHT
• SP724AHTP
• SP724AHT
• SP724AHTP

Design Notes:

Protection Application:

The signal lines used in a VGA port have a maximum frequency of 25 MHz, and are 0.7 Vp-p for R, G, and B lines, and 0.3 to 5.0 Vp-p for ID01, ID02, ID03, H-sync and V-sync. For these lines, the capacitance of the suppress needs to be taken into account.

Solution Description:

As shown at the left, discrete multilayer varistors can be used for board layout flexibility, or to reduce part count, two rail clamp devices can be used.

Companion Solutions:

Does not apply.

Regulatory Issues:

The IEC 61000-4-2 will be the most appropriate standard that applies for this port. It supplies a test method for verifying that the end product is not susceptible to ESD events.

Unique Features:

Does not apply.

Application Warnings:

Does not apply.