So I'm building a 12V-19V boost converter for automotive laptop use, and noticed the heatsink getting hotter than expected.
I tuned my snubbering, and while I'm awaiting a better rectifier, it still seemed like too much temp rise. Snubbering it actually seemed to do little for this.
I also suspected the MOSFET, since there are some inconsistencies in the datasheet.
The heading implies the part is 5.5mohm, but other specs within the same datasheet suggest 55mohm, off by a factor of 10!
So I connected a spare 24NF10 directly to a power supply, source to the negative binding post.
It's actually the same 14V bench supply I'm using to test the laptop booster, so the gate was tied to the positive binding post via a test lead.
I used my 4-ohm audio dummy load, so 3.5A went thru the drain. Instead of the expected ~18mV across the MOSFET, I measured 180mV! Yep, that's a ~50 milliohm part!
See datasheet for details.
Note: the Digikey summary for this part shows 60 milliohms.
This correlates to what I measured, albeit under lower Ids.
I tuned my snubbering, and while I'm awaiting a better rectifier, it still seemed like too much temp rise. Snubbering it actually seemed to do little for this.
I also suspected the MOSFET, since there are some inconsistencies in the datasheet.
The heading implies the part is 5.5mohm, but other specs within the same datasheet suggest 55mohm, off by a factor of 10!
So I connected a spare 24NF10 directly to a power supply, source to the negative binding post.
It's actually the same 14V bench supply I'm using to test the laptop booster, so the gate was tied to the positive binding post via a test lead.
I used my 4-ohm audio dummy load, so 3.5A went thru the drain. Instead of the expected ~18mV across the MOSFET, I measured 180mV! Yep, that's a ~50 milliohm part!
See datasheet for details.
Note: the Digikey summary for this part shows 60 milliohms.
This correlates to what I measured, albeit under lower Ids.
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