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Author Topic: The Bear of a Search  (Read 9348 times)

jadaro2600

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The Bear of a Search
« on: June 04, 2010, 06:31:00 AM »
I'm looking for links to places where I can search through electrical components for the lowest cut-on voltage in a transistor.

Has there been any website created devoted to this type of searching - I'm trying to locate, in essence, a database of multiple manufacturers' information.


jadaro2600

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Re: The Bear of a Search
« Reply #2 on: June 04, 2010, 07:18:48 AM »
Thank you, I'm looking for a transistor, NPN and PNP which have as low a voltage as possible for their cut-off, essentially, ..the point which the gate stops functioning and the transistor turns off.

I've been looking at Digikey; hopefully they'll send me a catalog.  the NTE catalog is huge, maybe I should go grab one of those, ...they actually have listings of these types of things.

jadaro2600

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Re: The Bear of a Search
« Reply #3 on: June 04, 2010, 07:41:58 AM »
The germanium style transistors are rather pricey.  ...the NTE100 and NTE101 are exactly the type of performance I'm looking for in a small signal low power transistor, but the per-piece price is around 11 dollars, US.

Pirate88179

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Re: The Bear of a Search
« Reply #4 on: June 04, 2010, 09:05:52 AM »
Jadaro:

As we have seen on the JT topic, the germanium transistors will work down to like .25 to .3 volts, maybe lower depending upon your circuit.

I have a few of these, hard to find but not all that expensive...IF you can find them.

Bill

gyulasun

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Re: The Bear of a Search
« Reply #5 on: June 04, 2010, 02:52:14 PM »
@jadaro

The correct term to search for is  ' low saturation transistor '

Zetex has been known as among the best, now they captured by Diodes Inc.  here is their link and enter the above key words:
http://www.diodes.com/search/index.php

You can find several other manufacturers with low saturation types:

http://www.sanyocomponentsdirect.com/Bipolar-Transistors/Bipolar-Transistors/Low-Saturation

http://www.onsemi.com/PowerSolutions/parametrics.do?id=808 

All these are bipolar Si transistors, with high Beta (hFE) (NOT Darlington), their base-emitter forward voltage is .7 - .8V.
Some of them seems to have better saturation voltage than a Germanium type, see here for instance, at Ic=100mA the sat voltage VCEsat=30mV,  this is the voltage drop between the collector-emitter:
http://www.onsemi.com/pub_link/Collateral/NSS1C201L.PDF

You may find them also by searching within bigger sellers pages like Future Electronics, Farnell, Digikey etc.

rgds,  Gyula

jadaro2600

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Re: The Bear of a Search
« Reply #6 on: June 05, 2010, 05:25:31 AM »
Ah, thank you gyulasun, having the correct terminology search helps.

Hopefully I'll acquire some of these transistors and do some testing, but I think I can do without them for now.  These will be for third of fourth stage of development, or there abouts.

I purchased so many components about a half a year, I may have one or two and not know it.  I'm pretty sure I would have skipped buying a 10 or 12 dollar component.