1. Home
  2. Electronics Design
  3. SMD Equivalents

SMD Equivalents

In updating an old design I find myself looking for some SMD equivalents to old favourites.

The three components I need new parts for are:-

2N3904 2N3906 1N4004

I would prefer to get as close a spec to each device as is practicable.

In the meantime I shall be browsing the datasheets and selectors

--

******************************************************************** Paul E. Bennett IEng MIET..... Forth based HIDECS Consultancy............. Mob: +44 (0)7811-639972 Tel: +44 (0)1235-510979 Going Forth Safely ..... EBA.
formatting link
********************************************************************
Reply to
Paul E Bennett
Loading thread data ...

MMBT3904

MMBT3906

Do you really need 400V?

If so, the DiodesInc S1GB-13 might work.

Digikey has the best part selector in the market.

Reply to
krw

Funny thing about those old JEDEC numbers is some (if not all) specified the package and electricals at the same time. So you can't make a surface mount version of say a 1n914 because that diode has to be in the glass package. I don't think it has to be in the clear glass, but just glass.

So if a surface mount part crossreferences to a JEDEC part, it is kind of cheating if you want to nitpick.

Reply to
miso

Thanks. I'll look those up. As to requiring 400V for the diodes, whilst that part of the circuit would not normally see such a voltage it is in an interface which could experience more than that as a trasnsient. The 1N4004 in the original circuit worked very well in the interfaces electrically noisy and hostile environment.

--
******************************************************************** 
Paul E. Bennett IEng MIET..... 
Forth based HIDECS Consultancy............. 
Mob: +44 (0)7811-639972 
Tel: +44 (0)1235-510979 
Going Forth Safely ..... EBA. www.electric-boat-association.org.uk.. 
********************************************************************
Reply to
Paul E Bennett

hmm.

formatting link

it's a 4148 I know, but it is smd and it is glass

-Lasse

Reply to
Lasse Langwadt Christensen

formatting link

Reply to
JW

As our assemblers like to say, the reason the package is called SOD-80 is because it is a ****ing sod when you try to pick it up. Shoots out of the tweezers across the room, rolls amazing distances on a table etc.

I started to design my very first SMD board using those (and the "mini-melf" resistors in a similar package). Only because I liked the familiar color bands on the resistors and the cathode marker on the diodes.

Soon saw the light on that one. Couldn't read the colors anyway, couldn't hold the parts.

--

John Devereux
Reply to
John Devereux

MMBT3904/PZT3904 (various manufacturers)

MMBT3906/PZT3906 (various manufacturers)

MRA4004 (On Semi)

Klaus

Reply to
Klaus Bahner

Yes, but they don't call it a 1N4148 because that would be a leaded package. That is my point. For the really old JEDEC parts, package and electricals are the same.

The 1n914/1n4148 are considered free. Not free as in beer, but really free. At least by old farts. But put them in surface mount, and they do have some cost, especially in a leaded package. [I don't know about the SODs, but they are a pain in the ass, at least for hand assembly.] The leaded package probably costs more than the die.

Unless the part is sexy (low noise, low leakage, wide bandwidth, yada yada yada), discrete semiconductors is an extremely low margin business.

Reply to
miso

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.