Since I don't find many datasheet errors, I thought I'd post this suspect.
Page 7 Fig 9
Notice the 1.5uF on Vo..
So Vo went from 5 to 1.5V in at most 1uS. (Rl = 1.9kohm. Table on page 3.)
Since i=Cdv/dt Then i=1.5uF(3.5/1uS)= 5.25amps ..yeah...ok. :(
btw...this is probably one of the most expensive linear optos I could find on Digikey.
D from BC myrealaddress(at)comic(dot)com BC, Canada Posted to usenet sci.electronics.design
It is a test circuit. That is meant to load the output.
Stored energy?
Yep, that's bogus, all right. Three possibilities for the intent: (1) misprinted units - it was jig capacitance (1.5pF?) (2) bypass capacitance intended, the 1.5 uF really connected to Vc (3) intent was to connect emitter to a load resistor, which only has low (circa 30 mV) output, but a followup comparator can get you to a good logic level.
I actually like (3), it speeds up optoisolators nicely, but probably it's (2).
I'm guessing it was a 1.5pF load from an active probe..
D from BC myrealaddress(at)comic(dot)com BC, Canada Posted to usenet sci.electronics.design
Yeah. Look at the output waveform.
It's a _test_ circuit, you know.
Hope This Helps! Rich
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