Optical Fiber Question

1 post / 0 new
Ruan's picture

Offline

Joined: Sep 14, 2020

Replies: 0
Optical Fiber Question
September 14, 2020 - 1:51pm

QUESTION:

If receiver is a transimpedance amplifier with an open loop gain of 200 and the average amplifier noise current is 2.7 pA/

Hz^0.5. The input resistance of the amplifier is 27 kΩ and the feedback resistance is 56 kΩ. The junction capacitance of the photodiode is 10 pF. Determine the photocurrent for the diode to maintain the required SNR of 50dB.



Answer

Ive used the formula B = G/(2*pi*Rf*C) to get the value of B, but I am unsure how to get Ip. I see the formula - Ip = (2*e*I*B)^0.5 , but not sure if this is the correct formula? How do I test if the satisfies my SNR value?



*This is an assignment question, don't want my work to be done for me, but I can't find the answer to this anywhere. Hope someone can help