For For your 1st stage, it is the bandwidth and the noise which need to be optimized.
Here is an expression for the traditional TIA stage (photodiode feeding the inverting input of an OPA directly) achievable bandwidth taken from the LMH6629 datasheet…
Hi Hooman,
Thank you very much for your help. I will try to use the OPA657 amplifier for the reasons you mentioned above. Also the evaluation board http://www.ti.com/tool/dem-opa-sot-1a looks suitable, since it can be used to build a differential input…
Andrew,
If you have 5-6mA of outnput current from the photodiode and you want about 2V output after the transimpedance stage, then 400Ohms of transimpedance gain should suffice. If so, the OPA846, OPA847 and OPA657 will be good amplifier choices.
…
Hi Javcel,
If you are concerned about the trans-impedance gain error, then I would suggest switching to standalone op-amp like the OPA657 or OPA659 which will provide better trans-impedance gain accuracy. I would recommend to use less than 1% tolerance…
I'am actually using LTspice. I have already imported the "pspice" models of OPA657, OPA847, … without trouble.
With the model you sent here is the result I obtain the following curve. The phase does not behave well, and the unity gain is not ok. If…
Hello James,
With a 3ns rise time one would ideally like a BW of 0.35/3 = 116MHz. The BW of a transimpedance amplifier is based on a couple of factors:
1. The photodiode capacitance. (The higher this capacitance the lower the BW when all other parameters…
Hello Serge,
The OPA847 and the OPA657 are some of our most popular high bandwidth amplifiers for transimpedance applications. The former has a BJT input stage which results in a higher bias current and the latter has a JFET input stage with very low…
Part Number: OPA656 Other Parts Discussed in Thread: TINA-TI , , OPA657 Tool/software: TINA-TI or Spice Models Ive been having the same problem for 2 weeks now with almost every OPA that i have downloaded from the TI website. i have a simple design and…
