Zener Test Jig

[muffy1975]

Hey guys,

I'm tryng to match for the TG and for 2254c


with this IGOR test JIG for Zener diodes i am getting results like 5.14v from one resistor and 5.01v from the other resistor.


If i find four diodes with the exact same measurements are these indeed matched as per the specification?


Or do the values need to be within 5mv of each other using the two resistors ie: 5.14v and 5.09v for example?


Thanks for any help here


Michael

 

[bruce0]

Be aware when doing close matching that there is quite a bit of temperature sensitivity (at least in forward drop, probably in avalanche too but I am not sure).

Match them at the same tempurature.  Use gloves or tweezers to put them in the rig.

As far as how close is close enough, it depends upon what you are matching them for.

 

[muffy1975]

I'm trying to match for the TG and for 2254c.


Do the two resistor results need to be within 5mv of each other?


Michael

 

[bruce0]

I'm trying to match for the TG and for 2254c.


Do the two resistor results need to be within 5mv of each other?


Michael

Sorry no idea of what match is needed.

 

[tommypiper]

I haven't done this test and lack any background info on it...

but it appears at first glance that there are two resistors there to give you results across a range of real world voltages.  Two data points is better than one, kind of thing...

Therefore, you are testing values with resistor A against one diode to the next diode.  And values with resistor B against one diode to the next.  The readings using resistor A and B do not need to match, they are two different data points which you want to use to match your diodes!  Hope that's clear. 

(You want your diodes to give the same readings between each other using resistor A, then again using resistor B.  You will thus have tested them with two voltages, instead of just one!)

 

[muffy1975]

thanks.

I got it.


Michael