Hi,
I am working on design using ONE8521T limiting TIA. It started off with the bare die characteristic testing whereby we tested on ONE8521T at range of voltage modulation from -22dBm to -68dBm. At -52dBm and -68dBm, the TIA is showing 30dB gain (although -68dBm is out of the device operating limit of 16uApp).
Then, we did wire bonding on the input pin and repeat the bare die characteristic measurement and found certain samples gain is drop from 30dB to ~26dB at modulation -52dBm. Here's my question:
1.) If the input signal is lower than / at the marginal of operating limit of 16uApp, how would the AGC behave? Will it turn off or showing reduction of gain?
2.) How does the TIA verify the input uApp current and determine the gain? Assuming I have random / periodic noise in my system and thus increase my uApp randomly / periodically. Would that higher uApp (contributed by noise) measured by TIA and thus determine a lower gain at ~26dB?
Appreciate your advice.
Thank you
-SY
