Need help reading P channel logic level MOSFET data sheets

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Wendy

Joined Mar 24, 2008
22,988
So I checked my stock for P channel logic level mosfets and I came up with these:

VP2206N3 MOSFET P channel
16N05L MOSFET P channel
P50N06 N Channel MOSFET

the only data sheet that explicitly showed it as a logic level was the 16N05L
would someone more knowledgeable than I please show me what G D voltage turns the MOSFET completely on?
 

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dl324

Joined Mar 30, 2015
14,902
the only data sheet that explicitly showed it as a logic level was the 16N05L
Logic level is a subjective term. What supply do you intend to operate at? At what current?
would someone more knowledgeable than I please show me what G D voltage turns the MOSFET completely on?
Datasheets specify a range for threshold voltage. That's usually the gate source voltage where the device just begins to turn, though I noticed that one of them specified threshold voltage at a current of 10mA.

VP2206 -1 - -3.5V @ Id = 10mA
15N05L 1-2V @ Id=250uA
P50N06 2-4V @ Id = 250uA

If you're operating with 3.3V logic, 15N05L would be considered logic level.

A typical VP2206 would be, but there's no guarantee you wouldn't get the device that requires -3.5V @ 10mA:
1658957363675.png
 

Papabravo

Joined Feb 24, 2006
18,978
The threshold voltage, Vgs(th) is only part of the story. The other thing you are looking for is a value of Vgs that that is equal to or allows an appreciable fraction of the absolute maximum current to flow through the channel. This can ONLY happen when rds(on), the resistance of the channel, is at or close to the minimum value that it can attain. This level of operation can be sustained continuously without straining the part or getting close enough to a limit to damage the part. We have hundreds (thousands(??)) of posts from people who burn up their MOSFETS because they are ignore this vital information.

For the 15N05L this is Vgs=5V and Id = 16A
Figure 6 of that datasheet suggests that most devices will be better than this at least in repetitive puls mode.
 

sagor

Joined Mar 10, 2019
714
Papabravo is correct. Look at the line that shows the Rds(on) resistance value. On that line, it will show at what Vgs voltage that value occurs at. Anything less, and you cannot be sure what the Rds(on) resistance actually is (some charts may show it).
Logic level MOSFETs show the Rds(on) at either the 5V or 4V level. Some will show at 3,3V, though that is not too common. Logic level is that 4V or 5V Vgs rating.
Two of your datasheets show Vgs at 10V to obtain the full Rds(on) value, too high for logic levels to fully turn on the MOSFET.
 
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