I am designing a TIA using inverter amplifier configuration. I am trying to figure the gain numbers obtained in the AC analysis.
Firstly, the TIA uses a resistor feedback configuration with input current set at 50uA, and the DC node voltage after simulation at the output is at 473 mV, this leads to a TI Gain of 20log(473m/0.05m)=79 dBohm
I checked it with the AC analysis plot of gain and the maximum turns out to be around 50dB
Now I am not certain about the procedure of determining the TI gain using ADE. I took a current source for the input whose ac magnitude is set to be 1 and Dc current as 50uA. After the simulations, I chose results>main form>selected the output node and dB scale. Is this is a right way to determine the transimpedance gain?
My guess is that looking at the DC values may not be helpful as a way of computing the gain because they almost certainly have some DC bias.
You could also check the transimpedance by running an "xf" analysis, and then specifying the output of the amplifier. Then after simulation, using Results->Direct Plot->Main form, pick xf, and then choose transimpedance and click on the input current source - it should then show you the gain that way (which I expect will match the ac result).
Thank you. It worked.