Automatic Gain Amplifier for Photodiode

well the transimpedance is the first issue, need

1. Source capacitance

2. desired gain

3. desired F-3dB

then your output AGC could use something like the VGA820 or a faster version is need be. 

To add on to Michael's response, this application report may also be helpful to you for selecting the best TIA for your application: link.

A lot has changed part wise since Hooman's app note, I actually did recently try to update the transimpedance state of the art solutions in this article - they broke the links to expand the figures/tables if you folks want the original pdf, let me know - private email, not public post. 

https://www.planetanalog.com/applying-high-speed-de-compensated-vfas-hitting-performance-targets-while-tuning-phase-margin-insight-10/

Hi Shashikant,

what signal range are we talking about?

Kai

Also, I did notice in Hooman's app note he was using the old equation from early ADI material for setting the feedback C. That simple approach is delivering a closed loop Q = 1, slightly peaked and ringy. 

Based on a series of 3 articles I wrote for BurrBrown in the late 90's, a  lot of the later high speed material improves this analysis quite a lot with minimal complexity - this forms the basis of a lot of later material - like this nice summary design discussion we were presenting from early 2002 on - this discussion is general, while tilted towards high speed decomp solutions, it applies generally. Once again, you need the true one pole GBP to get the right results - sometimes not exactly what is reported in datasheets. 

3733.Transimpedance design flow using high speed op amps.pptx

Hello all, 

Been going back and forth with Planet Analog - they are not going to fix those older articles they broke (no links to enlarge figures, tables) so here is the pdf that is pretty clear on Insight #10 - the back half of this is transimpedance design with part tables. 

Applying High Speed DeCompensated VFAs July1_2019.pdf

Hello Michael,

   Thank you for sharing the PowerPoint on transimpedance design and the original pdf; they are very helpful and insightful!

Sima

Hi Shashikant,

  Were you able to find products that fit your application? If not, would you be able to provide us with the information from Michael's and Kai's first replies?

Thank you,

Sima