Well, of course a vidicon tube scans thousands of photoresistors to get their output, and a CCD does the same with photodiodes.
Have you considered running 'several hundred' optical fibers as lightpipes, from the to-be-sensed locations to a linear CCD array?
Usually, one doesn't want a photodiode to charge up (because it has significant capacitance), but CCDs make that into a virtue, and you get a time-integration feature for free.
Rload of 562 ohm.
too
about 2.7 mA,
below the
very small
(2.048 V)
exposed to a
- that is
show any
drawn as
sense if
then -
gate-to-
and
gate-to-
the
the
-- Have you no responsibility for the minions you've taken on who depend on your work for their support? Have you no responsibility to customers who've been good to you and depend on you to support their needs? Methinks you have to work in order to accomplish those ends.
Rload of 562 ohm.
is too
Iabout 2.7 mA,
below the
very small
no
(2.048 V)
exposed to a
- that is
doesn't show any
on
drawn as
sense if
then -
gate-to-
- and
gate-to-
current, the
the
Some of it's grunt work, like manuals and parts lists and checking stuff. But overall it's a lot more fun that retiring and watching TV and playing golf or whatever.
But if you're saying that I have to work forever, out of obligation to somebody or other, that's just silly. Any time I want I can turn the company over to the kids and just tell them where to send the checks. But not any time soon.
One of my engineering lackeys just barged into my office with a six pack of Mirror Pond Pale Ale and forced me to drink one. He even made me open the bottle myself. Can't get no respect around here.
-- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation
Il 31/08/2012 19:14, Jamie ha scritto:
It depends of the kind of lamp. Anyway that noise is clearly visible (if any) and has nothing to do with the issue described.
Marco
Oh really? How would you know that?
If I were to use a 50% duty cycle light source on a PD, my DMM would register only 50% of the peek current and there for would lead to saying that the PD device is broke.
QUESTION :
DID YOU PUT A SCOPE ON THE OUTPUT TO VERIFY ?
If not, then you're just wasting peoples time.
Jamie
Il 01/09/2012 18:44, Jamie ha scritto:
Obviously. Otherwise how can I say "it is *clearly visible* ?
Thank you, it's very kind of you.
Marco
Jamie is one of Larkin's sycophants (or is it "sickophants" ?:-) and should be ignored/kill-filed.
Any response back from Intersil?
My guess is it's either a really bad batch, on the "slow" side of the process, or maybe it's just a dud design period... as drawn it _has_ to collapse at some high input level. ...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
Some modulation of the light input wouldn't explain the output foldback he's seeing.
-- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
Dodging the question does not answer it..
Your definition of clearly visible is still in the fog..
I can use a DMM a say it's clearly visible but it isn't
I'll just go with my feelings on this, and you don't need to know what they are.
Jamie
It's easy to demonstrate why the "folding" occurs... if anyone cares. ...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
So demonstrate it. You never say anything substantive any more; you just brag about what you can do without ever actually doing it.
Take into accout the probable mirror ratio.
-- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
I understand that however, his measuring tools most likely is not reporting the actual current he is getting before it folds back.
The point is, the device may actually be doing as advertised but may not be DC and there for the device being used to measure this will not report a DC current but one with a pulse which will just generate some average reading on DMM, which will be less than the expected value that was already expected to happen but only at a higher level.
It's all about the tools you use for doing this that makes a big difference in determining the factors.
We have current meters in line with devices that have a pulse on the line. In order to get a peak current reading we need to have a filter circuit on the meter to show that otherwise, it's just a calculated reading summed between the on and off and if you watch the meter it's all over the place.
I know my FLuke 289 I use when going out in the field will do this also in current mode. And even if I use the Peak function it still is a little flaky...
Jamie
Il 01/09/2012 19:01, Jim Thompson ha scritto:
Not yet.
I'm afraid it's a good guess...
Marco
Il 01/09/2012 20:05, Jamie ha scritto:
I exclude that. I measured the output signal with an oscilloscope first, and I saw a little 50/100 Hz noise only if I use a neon lamp. With incandescent lamps there is no ripple at all.
Furthermore, I experience the same odd behavior with sunlight, using some filters to increase the illumination gradually.
Marco
^^^^^^ Larkin needs to learn to spell as well ;-)
I did, in...
Date: Thu, 30 Aug 2012 07:40:59 -0700 Message-ID: [snip]
(1) It's ALL P-channel, mirror AND enable devices (2) The mirror is 1:M
No it's not obvious. You need to know at least the physical size of the PD, and what material it's made of... see for instance the number of DIFFERENT types available on XFAB processes... ah, yes, I see that Larkin has no clue... just lots of mouth but no brains.
BS... that's all you do... the only contradictions are in the vagueness of the datasheet... is it constructed like the "cartoon"? probably is. Now, tell me, Mr. Smartass, details of the enable device and the mirror... you can't.
BS, I ran it a couple of days ago.
Do you eat them, or just "stuff" them directly ?:-) ...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
saying
I SWAG'd M at 10, but the actual value looks to be closer to 11. Not a bad initial guess.
A self-proclaimed Master Circuit Designer like you should be able to look at the data sheet for a minute and estimate M, without using a calculator. It *is* obvious, and it is simple.
Do it. Now.
I can do a bunch of math analysis on this, and point out some interesting contradictions. And point out some additional measurements that Marco could do to maybe untangle things a bit. I will. Buy I'll allow you to do it first, if you can.
Do something real! Last chance!
-- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
Take a look at this sketch...
I replaced the upper P-channel "enable" device with a current source of value IDSS. (One of my special Spice tools... can't pull to infinity, stops at zero volts across it :)
Clearly, when the sum of Iphoto and M×Iphoto exceeds IDSS, the output will collapse.
(There's a multiplication symbol between "M" and "Iphoto"... in my fonts, maybe not in yours.)
The shape of that collapse will depend on the particular CMOS process it was made from. (A very sharp collapse would indicate that the "mirror" is actually made up as a cascode (maybe even combined with the enable device)... which is likely, if it was done properly.)
Without conducting testing with a calibrated light source, I can't tell whether it is you simply overloading the device above its design range, or if it is defective. ...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
ohm.
=A0 =A0 ...Jim Thompson
=A0 =A0| =A0 =A0mens =A0 =A0 |
=A0 | =A0 =A0 et =A0 =A0 =A0|
=A0|
=A0 =A0 =A0 |
ide quoted text -
Thanks Jim, I didn't know you could make a current mirror out of cmos.
There's a spec on the device page where it shows output current vs Lux. you'd have to convert lux to some 'real' unit of flux and calculate photons per second for the PD area. PITA, I can never remember the definition of lux. For any decent PD it is a 'pretty good' guess to assume every photon makes an electron.
George H.
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