Rui Longyuan Electronics
Rui Longyuan Electronics
cn en
Rui Longyuan Electronics
Rui Longyuan Electronics
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cn en


Circuit protection for DC input current - overvoltage and overcurrent


Protection application:
For LCD back lighter and microprocessor power, a DC voltage (typically in the range of 5VDC to 18VDC) will be supplied. Electrical threats include lightning surges, electrostatic discharge, and overcurrent conditions (short circuit or overload).
Solution description:
As shown on the left, a fuse or PTC can be used for short circuit and overload current situations. For surge and ESD protection, TVS diode (e.g. P4KE or P4SMA series) can be used.

Supporting solutions:

Note that when considering alternative solutions, the magnitude of the transient surge amplitude should be taken into account. For example, if the inrush current is too large, C-III or UltraMOV varistors or more powerful diodes (such as 600W, 1,500W) can be used. If the only threat is from electrostatic discharge, then multi-layer chip varistors are an option.

Regulatory issues:
If you need to consider electrostatic discharge, you can refer to IEC 61000-4-2 for test methods and transient waveform information that should be used.
Characteristics: Not applicable.
Application warning: Not applicable.