ADN2820: Optical fiber communication

Document created by analog-archivist Employee on Feb 23, 2016
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Since our Institute deals with optical fiber communication we are interested in
the 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


ADN2820 is a 10G TIA. We usually expect 0.2pF PD to work with the TIA for a
decent 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.