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Transimpedence amp project exercise

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awallin:

--- Quote from: Silente on January 20, 2020, 09:26:54 pm ---The specifications I want to respect are:
1. power of the incident radiation, when there is a signal of -30 dBm,
2. diode responsiveness = 0.8 A / W,
3. peak output voltage of at least 5 mV,
4. 50 Ohm output impedance,
5. input impedance < 50 Ohm,
6. band > 100 MHz.

--- End quote ---

you need to specify the photodiode size, which goes hand in hand with the photodiode capacitance, to fully specify the problem.
For 100 MHz you need small-ish photodiodes, maybe 1mm diameter or smaller, with capacitance 10 pF or lower.
like these maybe https://www.hamamatsu.com/resources/pdf/ssd/s5971_etc_kpin1025e.pdf

Silente:
Thank you to all.
I'll try to refine the schematic after your tips, and I will show calculations and simulations that I will do.
I'm downloading LTSpice.

Thank you again for now.

Marco:
Personally for a toy circuit like this I wouldn't use LTSpice ... can't stand the interface. Simetrix comparatively easier to work with for me and the free version is powerful enough for this.

magic:

--- Quote from: StillTrying on January 21, 2020, 12:39:09 pm ---It was 2 years ago on the LT 4 version, the 2 RF transistor's names were listed in "Pick a new transistor" but I only ever got the names visible - no other properties.

--- End quote ---
That's technically off topic, but since OP may run into the same gotcha:
The parameters that show up in "pick new transistor" are only informative and don't affect simulation. Many 3rd party models omit them, but they still work.

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