OPA3S2859-EP: OPA3S2859-EP

Hi again Vadim, 

For the oscillation, there is a footprint for a feedback capacitor across each gain resistor. You can use it to stabilize the 1kΩ gain based on the input capacitance value of the photodiode you want to simulate. What channel is this output for and what is wrong with it? Was the input a square wave? Does this have to do with your AC coupling?

Hi Sean,

I did not followed the layout. Took a shortcut, because the operating frequency is 500kHz. Presumed not much coupling can happen. I cannot reproduce the oscillation again. today it is just go to 27 mV DC. 00, 01 gives two gains and 10 this small DC. I as well noticed in 00, 01,11 current consumption is 44mA but at 10 it goes to 37mA.

Is there a reason for current to go lower at 10?

thanks vadim

Hi Sean,

I replaced 1 k with 10 k resistor and it is still the same problem, So it seems  is not related to feedback. The current decreased to 26 mA from 44mA

thanks vadim

Hi Vadim, I am a bit lost. Is this for our EVM or your new board? If it is a new board, can you post a schematic of the relevant and explain how the amplifier is being driven, and where this waveform was measured?

Hi Sean,

Can I sent it privately.

thanks vadim

Okay, my email is s-cashin@ti.com