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EMC GUIDELINES FOR MICROCONTROLLER-BASED APPLICATIONS

For air-discharge tests, the product is placed on a ground plane separated with 10 cm of insu-

lation.

Discharges are made on the ground plane.

A statistical method gives more reproducible results.

3.4.2.2 Fast Transients

This test consists of coupling these disturbances to the power supply or to the I/O of the MCU.

Fast transients are generated by switches or relays.

Fast transients are described in standard IEC.1000-4-4.

Figure 5. Disturbance Diagram

The spike frequency is 5 kHz. The generator produces bursts of spikes that last 15 ms every

300 ms.

ator must be used because the burst generators are too powerful to be directly applied to the

components.

Figure 6. Coupling Network

The fast transients are coupled to the I/O with a small capacitor.

0.1

0.5

0.9

50ns

5ns

300 ns

3

100 ns

To Power Supply

Decoupling Network

Power Supply Network

To the DUT

mm

mm