2N5457/8/9 equivalents ?

[Neeno]

Hi guys... it seems like mouser doesn't have a stock of those FETs anymore.
I checked Farnell too and a couple of EU parts supplier I buy from.
I'm more interested in 2N5458 and 2N5459... but I can't understand what is happening...
Are they really getting obsolete ?

Do you know someone who has them in stock ?

I'm open to equivalents too, but google isn't helping me much, and I don't know where to look.

Thank you for your help in advance.

 

[JohnRoberts]

It helps to address this as if you were specifying a part for a new design, if you can't source an original part.

Look at the circuit and determine from the PS rails what the max voltage is the part will see.

Then look at the control path to see what kind of pinch off voltage range it needs.

Then look a channel resistance needed to be compatible/effective.

You may be able to source a better part, that works better, perhaps requiring minor circuit tweaks.

JR

 

[pucho812]

I just went through this very same issue. 2n5459/7, etc are being obsoleted in the current to-92 package. however they are  now made in a sot-23 surface mount package and are readily available.

Some companies like small bear electronics still have the 2n5459's in a to-92 but in limited quantity and will only sell you a few pieces.

Mouser has them but only in the sot-23 surface mount package.

Fairchild semiconductor's new part number is

MMBF5459

so search mouser for that and you will find what you need...

 

[MartyMart]

Yup, getting hard to find, so glad that I have a bunch from a few years ago.

As said, smallbear and banzai have them so long as you don't need 100 at a time.

All Jfets and Mosfets seem to have gone up in price too.


On Ebay try sellers "6k8" and "DPI4Parts" or "DIY4Parts"

MM.

 

[My3gger]

You better ask Banzai before ordering anything. A friend just "bought" things like 6SN7 and some very regular caps along other regular things, they only had around half of this and no 6SN7 and caps that can be bought anywhere. They keep him sending the same wrong parts when he already have pcbs. It happened to me too a few years ago, but it wasn't that bad.
I would look at Tube Town, they have BF-245 which i think is similar part. Their stock is much bigger than it used to be...

 

[pucho812]

just put in a new sot-23 surface mount version, it will work the same and a pain in the ass to get in there I have managed to solder on legs and put it in as needed

 

[JohnRoberts]

If they are available in sot-23 you could probably make an adapter PCB, while sot-23 packages are big enough you could tack leads onto them, while i would be nervous about robustness of that for permanent repairs.

JR

 

[pucho812]

If they are available in sot-23 you could probably make an adapter PCB, while sot-23 packages are big enough you could tack leads onto them, while i would be nervous about robustness of that for permanent repairs.

JR

And here we go.
http://www.mouser.com/ProductDetail/Fairchild-Semiconductor/MMBF5459/?qs=sGAEpiMZZMv4z0HnGdrLjpo3FY8YkyPvExkmbt1wxk8%3d

 

[Silvas]

If your pads are in a triangle fashion you can just solder the SMD 5457 to the bottom of the board (check pin orientation). I've been doing this since Fairchild EOL'd the TO92 5457.

I even ordered 500 units from some store in China but they were too inconsistent (polarization)....the SMD's are just as good as the last TO92 ones i got from Mouser.

 

[MartyMart]

http://www.smallbearelec.com/servlet/Detail?no=310

http://www.smallbearelec.com/servlet/Detail?no=1275

Is that enough in stock or do you need several 100 ??

Marty.

 

[Neeno]

Thank you all guys !
I'll go for the SMD version and build a small adapter.