OPA855: 1 GHz APD receiver circuit design advice using the OPA855

Hyeonjoong Son

Part Number: OPA855

hello.
I am a beginner in TIA design and need some advice.

My target: APD receiver with up to 1Ghz response
Using APD: C30737LH-230-90C

Here is my schematic after reading the OPA855 datasheet and trying my think.
haven't tested it yet, but I think I need to modify something.
What do you think I should modify to achieve a 1Ghz response?
Any advice is appreciated.

9 months ago

+1 Michael Steffes 9 months ago

Guru 48195 points

hello,

Your C1 needs to be 0.27pF for stability, doing that will yield a Butterworth response with 830MHz F-3dB.

0 SimaJalaleddine 9 months ago

TI__Mastermind 24015 points

Hello Hyeonjoong Son,

I agree with Michael. You may be able to push it to closer to 900-950MHz cutoff frequency, but you will lose phase margin and it will alter your response (Q factor).

Layout is key to very high speed applications. I would recommend looking at our FAQ page under the transimpedance amplifier circuit section where we have popular threads, content, and calculators.

I also recommend reviewing this thread where Kai goes into detail about layout for TIAs using the OPA855. The most important aspect is to keep the photodiode as close to the input terminal of the amplifier as possible to avoid oscillations/instability due to board parasitics.

Thank you,

Sima