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How to lessen spike noise using MOS FET to perform switching operation?1010683

Latest Updated:09/02/2013

Question:

I am using a MOSFET to perform switching operation (0.5-5.0 MHz), and generating a square wave burst. I'd like to reduce the spike noise at the rise and fall of the wave. I'm considering using a product with small (35 ns) td(off). Would this be beneficial in reducing spike noise?

Answer:

Spike noise (ringing) generally originates in input capacitance. Ringing will be greater if input capacitance (Ciss) is low. Also, generally there is a relationship between Ciss and td(on)/td(off); if Ciss is low, td(on)/td(off) will also be small (fast). Therefore, products with high Ciss are suitable for reducing ringing. Please use a product of suitable Ciss according to your operating frequency.
Suitable Products
Power MOSFETs for General Switching