I always thought that the 1N4148 was an improved replacement for the obsolete 1N914, but I see that the 1N914 is still produced, and overmore, looking at the parameters for both on digikey they seem to be identical. What was the reason to create the 1N4148 if it's identical to the existing 1N914?
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compare the datasheets – PlasmaHH Apr 27 '15 at 08:48
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1@PlasmaHH: for Fairchild they're just one datasheet for both. – Joris Groosman Apr 27 '15 at 08:51
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1there are multiple other manufacturers of those diodes; for an in depth analysis of the possible market decisions it would be useful to analyze all of them to know what currentls is on the market. – PlasmaHH Apr 27 '15 at 09:00
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For a number of devices digikey (notably Fairchild) lists the leakage current for the 1N4148 as 5 µA, the same as the 1N914. But for others (e.g. NXP) the leakage current is only 25 nA. Which would make the 1N4148 a better alternative to the 1N914.
Joris Groosman
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1That's more of a Digikey issue- as is the differing PIVs. It's 25nA at 20V and 5uA at 75V. – Spehro Pefhany Apr 27 '15 at 14:06
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From Wikipedia:
Since leakage is usually an undesirable property, today manufacturers produce the 1N4148 and sell it as either part number.
Tom Carpenter
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WhatRoughBeast
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There are 1N914, 1N914A, 1N914B, 1N916, 1N916A, 1N916B, 1N4148, 1N4448, with fairly subtle differences between them.
Looking at the Fairchild datasheet, the guaranteed max capacitance is less for the 916A/B and 4448 than the 914A/B/4184 (2pF vs. 4pF), and the forward voltage min/max ratings differ, but there's nothing I see that prevents them all from being made with a single die.
In particular, there is no difference at all between part numbers on any of the 'typical' curves.
Spehro Pefhany
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