Rod Elliot P3A Layout - Critics

That's right, Fairchild is now part of On semi, as you are now aware and the datasheets of Fairchild products may still be headed with the Fairchild Semiconductor trademarks so others who copy the Onsemi datasheets don't change their references to Onsemi and no-one removes the superseded information on the web either. It's like reading long threads here where the OP was 10 years or more ago 🙄
 
AliExpress + genuine ON Semiconductors + excellent price does not compute. Sorry to disappoint asilva, but there is no way they can be new and genuine parts if they are available in small quantity at much less than US $4.00. World wide, the trade price is about $4.00 - $6.00 ea. depending on quantity.

They may be copies with something else inside or pulls (removed from scrapped equipment) and the leads restored to new condition. Of course, Onsemi's power transistors have a recessed, glossy label that is laser etched and few copies can match this feature. Check out the details before wasting your money on fake chips.

@luisitoloco, it was 2.35 a.m here, when I last posted (not sleeping well :xeye:)
 
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I also checked offers of up to 30 pairs for as little as 90 cents US (for each transistor). That seems like less than the manufacturer's production cost. The photos look genuine but what you receive may not be.
 
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the picture, duh...
 

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AliExpress + genuine ON Semiconductors + excellent price does not compute. Sorry to disappoint asilva, but there is no way they can be new and genuine parts if they are available in small quantity at much less than US $4.00. World wide, the trade price is about $4.00 - $6.00 ea. depending on quantity.

They may be copies with something else inside or pulls (removed from scrapped equipment) and the leads restored to new condition. Of course, Onsemi's power transistors have a recessed, glossy label that is laser etched and few copies can match this feature. Check out the details before wasting your money on fake chips.

@luisitoloco, it was 2.35 a.m here, when I last posted (not sleeping well :xeye:)

uh, try to sleep well 🙂
 
the picture, duh...

Yes, it is correct, but bear in mind that if you are going to power it at +/- 42v; q4 will heat up and a heatsink will be necessary for it, since it is polarized in class A, said transistor from rest (without input signal) gets hot, I remember that we did tests in the school laboratory, and that transistor without heatsink to inject a signal, it burned
with +/- 35v it would not heat, but anyway, in my design I left it far away to mount a separate heatsink.