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发表于 2020-1-7 00:42:06
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>47UH
What is the switching frequency?
I did some test on switching waveform on a MP4560 system designed for 1Mhz, and figured that: when the Vin rises from 14.2V to 36V, the MP4560 switching frequency will roll back from 1MHz down to 730KHz. The load is light at 5V Vout, about 160mA to 200mA.
Have you ever using a oscilloscope to monitor the switch frequency and watcing its changeing with Vin?
The other issue, I also observed is, MP4560 works better with large Inductor, the switching wave looks clean with 47UH inductor, if I switched to 8.2UH inductor with the same rated current parameter, the wave form distorts a lot. |
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