sazerac99us
New Member
While trying to select a MOSFET for a project, I see a lot of them incorporate a schottky diode. What is the purpose of this?
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sazerac99us said:While trying to select a MOSFET for a project, I see a lot of them incorporate a schottky diode. What is the purpose of this?
sazerac99us said:Yeah...I was cutting and pasting and it didnt work out. A lot of the data sheets that I've seen of MOSFETs have a diode or schottky diode in the symbol . Im planning on using a mosfets as a simple 12V switch, and also as reverse polarity protection (a regular diode will drop about .7 V, but with a mosfet, there would be less. (see figure D)
**broken link removed**
Sorry about the poor previous post.
Yeah...I was cutting and pasting and it didnt work out. A lot of the data sheets that I've seen of MOSFETs have a diode or schottky diode in the symbol . Im planning on using a mosfets as a simple 12V switch, and also as reverse polarity protection (a regular diode will drop about .7 V, but with a mosfet, there would be less. (see figure D)
Please explain. You're saying that reverse recovery energy is somehow going to break something when the channel is turned on?Never use the body diode for a protection diode. This diode is part of the mosfet structure and is "in use" while the mosfet is conducting. If it is trying to handle a reverse current when you turn the mosfet on, you can get some spectacular results ending with buying more mosfets.
It would seem to me that the extremely popular "synchronous rectification" process...
I still missed the point. How can activating a MOSFET while its body diode is in reverse recovery mode damage anything?The point I wanted to make is the difference between the body diode, which is the intrinsic diode that is formed as part of the mosfet structure, and a true reverse protection diode which is sometimes embedded into a mosfet, or just used externally.
I understand that the body diode ratings must be respected, but what is this reverse current problem? You're not referring to shoot-through on an H-Bridge due to timing problems?This diode is part of the mosfet structure and is "in use" while the mosfet is conducting. If it is trying to handle a reverse current when you turn the mosfet on, you can get some spectacular results ending with buying more mosfets.
I still missed the point. How can activating a MOSFET while its body diode is in reverse recovery mode damage anything?
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I still missed the point. How can activating a MOSFET while its body diode is in reverse recovery mode damage anything?
I understand that the body diode ratings must be respected, but what is this reverse current problem? You're not referring to shoot-through on an H-Bridge due to timing problems?