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Photodiode in UMC180nm

KhanAmir over 4 years ago

Hi,

I am unable to locate photodiode in UMC180nm PDK. Could you please help me?

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KhanAmir over 4 years ago

I am not sure it's availability. Usually we model it by current source and I thought may be it is there. Thanks
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KhanAmir over 4 years ago in reply to KhanAmir

Hi again, this is positive half clipper or positive wave rectifier but giving output other way.
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KhanAmir over 4 years ago in reply to KhanAmir
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Andrew Beckett over 4 years ago in reply to KhanAmir

KhanAmir said:
Hi again, this is positive half clipper or positive wave rectifier but giving output other way.

Did you have a question? I don't see anything obviously wrong here (of course, I don't know what your diode model "mymodel" looks like).

Andrew
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Andrew Beckett over 4 years ago in reply to KhanAmir

KhanAmir said:
Hi again, this is positive half clipper or positive wave rectifier but giving output other way.

Did you have a question? I don't see anything obviously wrong here (of course, I don't know what your diode model "mymodel" looks like).

Andrew
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KhanAmir over 4 years ago in reply to Andrew Beckett

Yes, this is positive clipper but as you can see in the waveform positive waveform is not clipped. Diode mode "mymodel" is simply defined AS "model mymodel diode is=1.8e-5 rs=1.43 n=1.22 bv=100 m=0.5 phi=0.7". Why it is giving the opposite than expected?
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Andrew Beckett over 4 years ago in reply to KhanAmir

OK, from a quick google search for "positive clipper" (just to make sure I had the terminology right and it was supposed to be removing the positive parts rather than preserving them), as well as just reasoning about the circuit, it's pretty clear that your circuit is wrong. You have the resistor and the diode swapped. Here's one such search result.

If you swap the diode and resistor, it will work as you expect.

Andrew
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KhanAmir over 4 years ago in reply to Andrew Beckett

Ohh my blunder! Sorry to bother you. Thanks a lot
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