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Jan Panteltje <alien@comet.invalid> wrote:
https://www.electronicdesign.com/technologies/analog/article/55250719/phlux-technology-tailoring-the-design-of-transimpedance-amplifiers-to-infrared-sensor-apps-part-2
I just drive the photo diode directly into the base of an NPN .....
(ducks).
ThatÆs basically a homebrew phototransistor, and may work great for >applications that donÆt require high speed, low noise, or accurate >calibration. (There are lots of those.)
A slightly more advanced method is to replace the NPN with a cheap MMIC >amplifier. If you have at least a milliamp of photocurrent, thatÆll get you >close to the shot noise, and itÆll be pretty fast unless the PD itself is >slow.
We sell fancier photoreceivers for much dimmer light, where itÆs more >difficult to preserve both low noise and wide bandwidth.
Cheers
Phil Hobbs
On Fri, 27 Dec 2024 14:14:31 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
Jan Panteltje <alien@comet.invalid> wrote:
https://www.electronicdesign.com/technologies/analog/article/55250719/phlux-technology-tailoring-the-design-of-transimpedance-amplifiers-to-infrared-sensor-apps-part-2
I just drive the photo diode directly into the base of an NPN .....
(ducks).
Thats basically a homebrew phototransistor, and may work great for
applications that dont require high speed, low noise, or accurate
calibration. (There are lots of those.)
A slightly more advanced method is to replace the NPN with a cheap MMIC
amplifier. If you have at least a milliamp of photocurrent, thatll get you >> close to the shot noise, and itll be pretty fast unless the PD itself is >> slow.
We sell fancier photoreceivers for much dimmer light, where its more
difficult to preserve both low noise and wide bandwidth.
Cheers
Phil Hobbs
MMICs are. But be aware
that some, the newer self-biasing kind, get very weird at low
frequencies, and the data sheets hide it.
An oldie but goodie from your humble servant:
“photodiode front ends: the real story” https://electrooptical.net/static/oldsite/www/frontends/frontends.pdf
Cheers
Phil Hobbs
https://www.electronicdesign.com/technologies/analog/article/55250719/phlux-technology-tailoring-the-design-of-transimpedance-amplifiers-to-infrared-sensor-apps-part-2
I just drive the photo diode directly into the base of an NPN .....
(ducks).
https://www.electronicdesign.com/technologies/analog/article/55250719/phlux-technology-tailoring-the-design-of-transimpedance-amplifiers-to-infrared-sensor-apps-part-2
I just drive the photo diode directly into the base of an NPN .....
(ducks).
On Fri, 27 Dec 2024 13:45:15 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
https://www.electronicdesign.com/technologies/analog/article/55250719/phlux-technology-tailoring-the-design-of-transimpedance-amplifiers-to-infrared-sensor-apps-part-2
I just drive the photo diode directly into the base of an NPN .....
(ducks).
I just drive it into the emitter of an NPN. That's my Tough TIA
circuit.
john larkin <JL@gct.com> wrote:
On Fri, 27 Dec 2024 13:45:15 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
https://www.electronicdesign.com/technologies/analog/article/55250719/phlux-technology-tailoring-the-design-of-transimpedance-amplifiers-to-infrared-sensor-apps-part-2
I just drive the photo diode directly into the base of an NPN .....
(ducks).
I just drive it into the emitter of an NPN. That's my Tough TIA
circuit.
Also a strong choice if youÆve got at least a few microamps of
photocurrent. Biasing the CB stage with a quiet current source is a win for >slightly faster things.
Then if your photons are valuable, you can get into closed-loop
bootstrapped bootstraps and fancy stuff like that, and wind up with
something like our
QL01 (10M ohms, 7 sq mm, 1 MHz, shot noise limited above 25 nA in the full >BW) or its just-introduced little brother the
QL03 (1M ohms, 700 kHz, 150 sq mm, shot noise limited above 60 nA).
Cheers
Phil Hobbs
On Fri, 27 Dec 2024 13:45:15 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
https://www.electronicdesign.com/technologies/analog/article/55250719/phlux-technology-tailoring-the-design-of-transimpedance-amplifiers-to-infrared-sensor-apps-part-2
I just drive the photo diode directly into the base of an NPN .....
(ducks).
I just drive it into the emitter of an NPN. That's my Tough TIA
circuit.
On Fri, 27 Dec 2024 08:12:23 -0800, john larkin <JL@gct.com> wrote:
On Fri, 27 Dec 2024 13:45:15 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
https://www.electronicdesign.com/technologies/analog/article/55250719/phlux-technology-tailoring-the-design-of-transimpedance-amplifiers-to-infrared-sensor-apps-part-2
I just drive the photo diode directly into the base of an NPN .....
(ducks).
I just drive it into the emitter of an NPN. That's my Tough TIA
circuit.
John, ISTR we made a deal about not feeding the trolls?
On Fri, 27 Dec 2024 08:12:23 -0800, john larkin <JL@gct.com> wrote:
On Fri, 27 Dec 2024 13:45:15 GMT, Jan Panteltje <alien@comet.invalid> >>wrote:
https://www.electronicdesign.com/technologies/analog/article/55250719/phlux-technology-tailoring-the-design-of-transimpedance-amplifiers-to-infrared-sensor-apps-part-2
I just drive the photo diode directly into the base of an NPN .....
(ducks).
I just drive it into the emitter of an NPN. That's my Tough TIA
circuit.
John, ISTR we made a deal about not feeding the trolls?
On 12/27/24 19:16, Cursitor Doom wrote:
On Fri, 27 Dec 2024 08:12:23 -0800, john larkin <JL@gct.com> wrote:
On Fri, 27 Dec 2024 13:45:15 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
https://www.electronicdesign.com/technologies/analog/article/55250719/phlux-technology-tailoring-the-design-of-transimpedance-amplifiers-to-infrared-sensor-apps-part-2
I just drive the photo diode directly into the base of an NPN .....
(ducks).
I just drive it into the emitter of an NPN. That's my Tough TIA
circuit.
John, ISTR we made a deal about not feeding the trolls?
Troll? I think he sparked an interesting discussion. The TIA
amplifiers you typically see in application notes are very poor.
It's good to show people here that there are ways to do much
better.
Jeroen Belleman
Jeroen Belleman <jeroen@nospam.please> wrote:
On 12/27/24 19:16, Cursitor Doom wrote:
On Fri, 27 Dec 2024 08:12:23 -0800, john larkin <JL@gct.com> wrote:
On Fri, 27 Dec 2024 13:45:15 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
https://www.electronicdesign.com/technologies/analog/article/55250719/phlux-technology-tailoring-the-design-of-transimpedance-amplifiers-to-infrared-sensor-apps-part-2
I just drive the photo diode directly into the base of an NPN .....
(ducks).
I just drive it into the emitter of an NPN. That's my Tough TIA
circuit.
John, ISTR we made a deal about not feeding the trolls?
Troll? I think he sparked an interesting discussion. The TIA
amplifiers you typically see in application notes are very poor.
It's good to show people here that there are ways to do much
better.
Jeroen Belleman
An oldie but goodie from your humble servant:
“photodiode front ends: the real story” https://electrooptical.net/static/oldsite/www/frontends/frontends.pdf
Cheers
Phil Hobbs
On 12/27/24 21:14, Phil Hobbs wrote:
Jeroen Belleman <jeroen@nospam.please> wrote:
On 12/27/24 19:16, Cursitor Doom wrote:
On Fri, 27 Dec 2024 08:12:23 -0800, john larkin <JL@gct.com> wrote:
On Fri, 27 Dec 2024 13:45:15 GMT, Jan Panteltje <alien@comet.invalid> >>>>> wrote:
https://www.electronicdesign.com/technologies/analog/article/55250719/phlux-technology-tailoring-the-design-of-transimpedance-amplifiers-to-infrared-sensor-apps-part-2
I just drive the photo diode directly into the base of an NPN ..... >>>>>> (ducks).
I just drive it into the emitter of an NPN. That's my Tough TIA
circuit.
John, ISTR we made a deal about not feeding the trolls?
Troll? I think he sparked an interesting discussion. The TIA
amplifiers you typically see in application notes are very poor.
It's good to show people here that there are ways to do much
better.
Jeroen Belleman
An oldie but goodie from your humble servant:
“photodiode front ends: the real story”
https://electrooptical.net/static/oldsite/www/frontends/frontends.pdf
Cheers
Phil Hobbs
Yes, that one made me take notice.
Jeroen Belleman
On Fri, 27 Dec 2024 18:16:44 +0000, Cursitor Doom <cd@notformail.com>
wrote:
On Fri, 27 Dec 2024 08:12:23 -0800, john larkin <JL@gct.com> wrote:
On Fri, 27 Dec 2024 13:45:15 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
https://www.electronicdesign.com/technologies/analog/article/55250719/phlux-technology-tailoring-the-design-of-transimpedance-amplifiers-to-infrared-sensor-apps-part-2
I just drive the photo diode directly into the base of an NPN .....
(ducks).
I just drive it into the emitter of an NPN. That's my Tough TIA
circuit.
John, ISTR we made a deal about not feeding the trolls?
His post was reasonable and on-topic, and he didn't insult anyone, and
TIAs are interesting.
Transistor betas are all over the place, but alphas are very
predictable.
Jan Panteltje <alien@comet.invalid> wrote:
https://www.electronicdesign.com/technologies/analog/article/55250719/phlux-technology-tailoring-the-design-of-transimpedance-amplifiers-to-infrared-sensor-apps-part-2
I just drive the photo diode directly into the base of an NPN .....
(ducks).
That’s basically a homebrew phototransistor, and may work great for >applications that don’t require high speed, low noise, or accurate >calibration. (There are lots of those.)
A slightly more advanced method is to replace the NPN with a cheap MMIC >amplifier. If you have at least a milliamp of photocurrent, that’ll get you >close to the shot noise, and it’ll be pretty fast unless the PD itself is >slow.
We sell fancier photoreceivers for much dimmer light, where it’s more >difficult to preserve both low noise and wide bandwidth.
