Q
Since our Institute deals with optical fiber communication we are interested inthe following device: TIA ADN2820.
Unfortunately I could not find an information on the 3dB bandwidth depending on
the photodiode capacitance. Since we are using bigger photodiodes (larger
capacitance) we are interested in the 3dB Bandwidth for a photodiode
capacitance from 0.3pf to 2pf. Is it possible to get this additional
information?
A
ADN2820 is a 10G TIA. We usually expect 0.2pF PD to work with the TIA for adecent 10G quantizer output performance.
Please note, the digital knee frequency is about Fknee = 0.3/Tr. For a 10G
signal, the Tr is about 25ps so Fknee = 12GHz.
In general, a 10G signal should have at least 8GHz bandwidth.
At a reverse biased condition, the ac impedance of the PD is close to a fix
number. The larger capacitance leads to a long time constant
And worse rise / fall times. So limited the expected 10G performance.