Improperly tested LEDs can cause electrical stress damage: do you know why?

Most LEDs can emit light with forward bias, and generally do not operate with reverse bias. LEDs consist of a PN junction that can be destroyed by excessive current flow if a high voltage surge passes through the device in the opposite direction.

Q: Types and causes of electrical stress damage during LED testing

Sometimes LEDs can be damaged during testing without the engineer noticing the situation. Special care must be taken not to overload the LEDs during testing.

Talking about the insulation safety standard of driver chip

Test engineers should also be aware of electrical stress damage (ie, electrical overload) during testing. There are mainly three cases:

1. Electrical Overload (EOS):

EOS threats are mainly attributed to poor handling and/or test fixture design issues;

Surges from nearby lightning strikes and equipment switching can generate severe transient energy on power and data lines.

2. Electrostatic discharge (ESD):

• Charged objects (including people) touching ESD-sensitive (ESDS) items;

• A charged ESDS device touches ground or another conductive object at a different potential;

• ESDS devices are grounded when exposed to electrostatic fields.

LED manufacturers recommend guidelines for preventing and managing ESD/EOS threats. The IEC 61340-5 and ANSI/ESD S20.20 standards provide guidelines for preventing EOS and ESD damage when assembling LED components in a system.

3. Directional polarization:

Most LEDs can emit light with forward bias, and generally do not operate with reverse bias. LEDs consist of a PN junction that can be destroyed by excessive current flow if a high voltage surge passes through the device in the opposite direction.

LED manufacturers generally recommend using Zener diodes for system testing before installing LEDs.

The Links:   CM100DY-24NF DMC-50799