I seem to recall the IRF830 has a built in protection diode. Or is this part also so 2010's? Want to use it for tube work, more than 1W dissipation. What are all the new kids using now?
They have lots, but the minimum order is 75 pcs. Not bad for $50 total order.
https://www.win-source.net/stmicroelectronics-irf820.html
https://www.win-source.net/stmicroelectronics-irf820.html
The reverse diode is an intrinsic one; it comes built into the transistor. It's good to use an external diode that is beefier than the internal one, however, especially if the transistor is used to switch inductive loads.
It's not on the datasheet. So you better not bet on it.
"Gate-source voltage VGS ±20V"
"+20V G-S" is meaningless if they put a 1V diode on the gate.
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I'm a fan of IXYS...
How about this? https://www.digikey.ca/en/products/detail/ixys/IXTP2N65X2/5361078
How about this? https://www.digikey.ca/en/products/detail/ixys/IXTP2N65X2/5361078
The Zener may be 20V one way but almost invariably 0.6V the other way. It is just a "regular diode" with a specified breakdown.
You can accidentally bias the G-S in the reverse direction and sneak past that diode to clobber the transistor.
The passive GS one is irrelevant here, since it will always be reverse biased , plus no inductive switching, all loads are resistive.
A reverse biased GS Zener is fine, we work in the positive quadrant here and chopping negative voltages to -0.7V or -20V is the same, MosFet is turned OFF with negative voltages, nothing useful there.
If deemed important, series back to back 20V Zeners work fine and are symmetrical by definition.
A reverse biased GS Zener is fine, we work in the positive quadrant here and chopping negative voltages to -0.7V or -20V is the same, MosFet is turned OFF with negative voltages, nothing useful there.
If deemed important, series back to back 20V Zeners work fine and are symmetrical by definition.