1N4148 - Anything better?

[maicael]

Hello,
Don't know if I can post it here but I won't to ask about the popular signal diode 1N4148 as it is a silicon diode and can handle high frequency.
My main question-is there any rival (ultra fast) signal germanuim signal diode or schotkey signal diode that can outperform the 4148 silicon diode.the ultrafast is really emphasized.
Just wondering as 4148 seeems so popular

 

[Pommie]

Yes.

 

[JimB]

Why don't you just tell us what it is you are trying to do?

Or is this just general curiosity about signal diodes?
In which case the answer is yes, there are many diodes which can outperform a 1N4148, but at the moment I cannot give you a type number off the top of my head.

JimB

 

[ronsimpson]

silicon diode and can handle high frequency

High Frequency is not that simple.
1N4148 shows 2pF and 4nS.
I can find much faster than 4nS but the capacitance goes up.
I can find special low capacitance diodes but the price goes up.
What is you idea of high frequency? Micro Wave?

 

[Ian Rogers]

This is impossible to answer... It all depends on forward current and voltage..... The 1n1418 is a cracking diode for the parameters it fits into....

 

[Willen]

I heard that 1N34 types of all germenium diodes can outperform 1N4148 as signal diode. I have some 1N5711 schottky diode too.

 

[maicael]

Honesty its curiosity. Everywhere I turn its 4148.
I mean we have lots of diodes so why this diode all the time.
As Rogers said its parameters make it a cracking diode

 

[Nigel Goodwin]

Honesty its curiosity. Everywhere I turn its 4148.
I mean we have lots of diodes so why this diode all the time.

Because it's a cheap general purpose silicon diode - I doubt that all of them supplied as such are actually IN4148's, but just a diode with a similar spec. (many 1N4148's have no numbers on them).

 

[ronsimpson]

I heard that 1N34 types of all germenium diodes can outperform 1N4148 as signal diode.

Outperforms?.....not as good about leakage.

A race car outperforms a bicycle, but it does not do well on the bicycle path.

 

[crutschow]

The 1N4148 is a cheap, general-purpose diode and is thus often used where its general-purpose specs will meet the requirements of the application. Other similar diodes could likely also be used instead, but the 1N4841 seems to occupy that position by default.
If you need a diode with other requirements, such as ultra-fast switching or RF detection, then other diode types will likely perform better. In those situations the diode is selected on a case-by-case basis.

A extreme example of diode specialization is the precise (accurate square-law) envelope detection of mV GHz RF signals. The NASA satellite I worked on used Back Diodes (tunnel type diodes operated in the reverse direction) for this purpose since they gave the best performance in that application. But that diode would be ill-suited to most other applications since its maximum reverse voltage rating is less than a volt.

 

[ronsimpson]

Be thankful there is a 1n4148 much like a 2n2222a.

 

[KMoffett]

And 2N3904's and 2N3906's... but curse the fact that people still want to use LM741s and 2N3055s.

Ken

 

[MaxHeadRoom78]

Personally my preference is Mosfets where possible.
Rarely use bi-polar now.
Max.

 

[Nigel Goodwin]

Personally my preference is Mosfets where possible.

That seems a very 'American' attitude

The rest of the world, and almost all manufacturers would seem to disagree though.

 

[mvs sarma]

Semtech electronics has 1n60p diodes and it is germanium point contact.
i bought 100lot from e-bay and able to match set of 6 and I could manage 14 sets.
here is the datasheet

 

[Willen]

Semtech electronics has 1n60p diodes and it is germanium point contact.
i bought 100lot from e-bay and able to match set of 6 and I could manage 14 sets.
here is the datasheet

Hi, Sorry for asking unrelated thing, but why you match set of 6 and manage 14 sets? Confused what you were saying.

And from were you bought part from ebay and from where they delivered to you there in India? Maybe was expensive.

 

[MaxHeadRoom78]

That seems a very 'American' attitude

The rest of the world, and almost all manufacturers would seem to disagree though.

Not sure why it would be 'American'?
When interfacing with Pic's/TTL/CMOS etc the logic level Mosfets (2n7000 etc) were designed for the purpose.
Practically all servo and spindle drives now use power Mosfet's for PWM outputs, some IGBT's.
Max.

 

[MikeMl]

Nigel, why are you not using 12AX7s for interfacing between a PIC and a relay. This would be a truly 'British' solution

 

[Nigel Goodwin]

Nigel, why are you not using 12AX7s for interfacing between a PIC and a relay. This would be a truly 'British' solution

Certainly wouldn't be - as a 12AX7 is an American valve

If you'd said ECC82 or similar, you might be closer.

 

[Nigel Goodwin]

Not sure why it would be 'American'?

Because it's only ever American members here who make such suggestions - and certainly "MOSFET's where possible" is a crazy idea, why not MOSFET's where they are most suitable, and BIPOLAR where they are most suitable? (and for MikeML - valves where they are most suitable ).