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DIY Stompboxes => Building your own stompbox => Topic started by: chumpito on August 04, 2004, 04:33:04 PM

Title: Fairchild J201
Post by: chumpito on August 04, 2004, 04:33:04 PM
I'm attempting a pcb design for jinx and up until now I assumed the pinouts for all transistors was the same regardless of manufacturer.  Is this a mistake with the data sheet or is this a common thing?
Fairchild (http://www.fairchildsemi.com/ds/J2/J201.pdf)
Vishay (http://www.vishay.com/docs/70233/70233.pdf)

I'm not sure what kind I have :?
Title: Fairchild J201
Post by: Elektrojänis on August 04, 2004, 04:38:08 PM
To me it looks like they are the same... Am I blind?
Title: Fairchild J201
Post by: nightingale on August 04, 2004, 04:56:58 PM
that  is pretty common pinout IMO~
the only j201's that i have not had to "cross the legs"... were a batch i got from smallbear..
hth,[/i]
Title: Fairchild J201
Post by: chumpito on August 04, 2004, 05:37:59 PM
Quote from: nightingalethat  is pretty common pinout IMO~
Does that mean you're saying that it's a common occurance or that one of them is the common pinout? :?

Quote from: nightingalethe only j201's that i have not had to "cross the legs"... were a batch i got from smallbear..
Well at least I wouldn't have to cross the pins with this one, just reverse it, but still, if I were a manufacturer that would seem like a ridculous thing to have to deal with whenever you get in a new shipment of transistors.
Title: Fairchild J201
Post by: spongebob on August 04, 2004, 06:08:05 PM
The Vishay datasheet shows it from the top, maybe that's what's causing the confusion... holding them with the pins down, facing the flat side, it's D - S - G for both of them, or am I blind too?
Title: Fairchild J201
Post by: niftydog on August 04, 2004, 07:45:19 PM
I'm with spongebob, that Vishay datasheet is terrible! Top view makes it confusing.

Pins down, looking at the flat side they're both DSG.
Title: Fairchild J201
Post by: chumpito on August 04, 2004, 08:41:49 PM
Quote from: spongebobThe Vishay datasheet shows it from the top...

DOOH! Top view. :oops:
Title: Fairchild J201
Post by: Mike Burgundy on August 06, 2004, 06:14:50 PM
Be warned though - some manufacturers DO differ for some BJ's and (...)FETS.
It's rare IMHO - only come across an occurrence of different pinout than the "whatever brand" sheet I had lying around myself- but  it does happen. Frustrating.
Title: Fairchild J201
Post by: Peter Snowberg on August 06, 2004, 06:40:03 PM
I've seen more than one PCB that had pads for two pinouts of the same transistor. If you're making a PCB layout, it's worth thinking about. :D
Title: Fairchild J201
Post by: Paul Perry (Frostwave) on August 07, 2004, 01:50:24 AM
Quote from: Peter SnowbergI've seen more than one PCB that had pads for two pinouts of the same transistor. If you're making a PCB layout, it's worth thinking about. :D
I bet you do it for multiturn trimpots too, right? :wink:
Title: Fairchild J201
Post by: mikeb on August 07, 2004, 05:46:53 AM
Rick L made a good suggestion to me - use an inline arrangement for FETs and BJTs so that a) different pinouts can be accomodated and b) those snap-off IC pins can be used as sockets (100 mil spacing) and hence different parts experimented with.

Mike