EL7900

It looks as if the data-sheet data was taken from a sample from a rather better batch than the one that provided the parts that got shipped to you.

Batch-to-batch variation is often larger that within-batch variation.

-- Bill Sloman, Nijmegen

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So what did you think that your contribution added to the thread? Did you feel that your "most prolific poster" status might be be under threat, so you needed to make the kind of contribution that Google will count, even if everybody will see it as contentless?

I'm not enough of an ass to add an entirely pointless comment to a thread.

I don't, as I seem to have mentioned before. Technically speaking, I'm retired, rather than unemployed, but getting that right would seem to require a kind of civility that you seem unlikely to master, but complain about failing to get from other people.

In your depressingly inadequate excuse for a mind.

-- Bill sloman, Nijmegen

ohm.

I agreed with you, and you responded with sarcasm. Small wonder that nobody wants to work with you.

John F, Study the mirror schematic... excessive photo current multiplied by the mirror ratio could exceed IDSS on the enable device. ...Jim Thompson

did you put a piece of glass over the top of the sensor?

Jamie

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Any small silicon PD should work fine, as long as the shift reg has open-drain outputs. Alternatively you can use a tri-state buffer with its input grounded, and its output enable pin controlled by the shift register. That's essentially equivalent to an open-drain part.

I did this sort of thing a fair amount using zero-power PALs about 15 years ago. If you use them carefully, and keep the supplies clean as a whistle, CMOS digital parts have a lot of good analogue uses.

Cheers

Phil Hobbs

datasheet states that; output is not short circuit protect and must never exceed 6mA, if you use a load resistor less than 800R you may damage the device with strong input light,

-Lasse

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You didn't - in fact - include any explicit reference to my comments. As far as your - minimal - content went, it would have made just as much sense as a reaction to Marco Trapanese's original post.

"Yup, looks like a bug. Too much light breaks it."

You'd like to think so. More objective observers might favour John Field's point of view - I certainly do, but I'm scarcely objective.

-- Bill Sloman, Nijmegen

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WTF is wrong with you? I replied directly to your post. I agreed with you. You are insane.

You're both insane and both unemployed. You deserve one another. Enjoy.

Of course, if you have hundreds of these things connected to one summing junction, you're going to have to worry about pickup and instability. OTOH ambient light sensor parts aren't usually used where speed is an issue, so a big capacitor across the feedback resistor would help a lot. I'd still probably use several op amps and a MUX to switch between their outputs.

Cheers

Phil Hobbs

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Oh I see, you favor what ever grass is greener at the moment.. I can see where this is going.

Jamie

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Jamie

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I can't see what either of those sour old hens ever favor. They are truly hopeless.

Il 29/08/2012 01:40, snipped-for-privacy@fonz.dk ha scritto:

I may damage it because the strong input light leads to an output current above 6 mA. But this *does not* happen.

Marco

Il 29/08/2012 01:08, John Fields ha scritto:

As said to Phil Hobbs I just need to scan an array of several hundred of photodiodes in order to get their output.

Marco

Il 29/08/2012 02:56, Phil Hobbs ha scritto:

Yes.

It's exactly what I did. I have 4 independent lines with 112 sensors each one. I scan them together.

Marco