PIN photodiode & TIA question

Sep 17, 2005 1 Replies

formatting link

I have an article on my web site that has this, with detailed design steps.

formatting link
about halfway down.

Cheers,

Phil Hobbs

Hi everybody.



I am going to use S7481 photodiode as high speed photodetector for 100Mbit/s free space optical link. It is high speed photodiode (Cut-off frequency 500MHz) with high sensitivity in visible range

formatting link
but it has high junction capacitance - 6pF. I have MAX3657 transimpedance amplifier (TIA)
formatting link
But it optimized for 0.5pF capacitance photodiodes. For 0.5pF MAX3657 has



130MHz signal bandwidth, for 1.5pF bandwidth is 50MHz. It less than 75Mhz, needed for 100Mbit/s. Not only bandwidth decreased, input referred noise level increase also.

Can I loss sensitivity but reach 75Mhz bandwidth on S7481 + MAX3657? Or I need other solution ? What would you recommend ?


-- with best regards Roman


Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required