Re: Mild OT question – Checking diodes


Robert Simpson
 

So would 3-4V AC work for the EB junction in Transistors with low VEBO? For others I guess I would need to look at the spec for each transistor type tested.
Bob

--- In TekScopes@yahoogroups.com, David <davidwhess@...> wrote:

Usually you limit the test current so when the junction goes into
reverse breakdown, it does not fail however . . .

Reverse bias breakdown of a bipolar transistor's EB junction will
degrade the hfe of the transistor. In a lot of applications this will
not matter but in circuits that rely on high hfe, it will ruin them.

Precision differential input stages include bootstrapping or back to
back input diodes to prevent EB breakdown.

On Mon, 08 Apr 2013 02:50:02 -0000, "Robert"
<go_boating_fast@...> wrote:


So how do you test transistors safely? I would like to use my 12V AC
diode test setup but looking at a transistor spec this doesn't seem
safe. For example the 2N3906 shows 5V VEBO.
Bob

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