ADS6145: Recommended value for the filter constant of the ADC input part from the fully differential amplifier.

Hi, Rob

Rob Reeder said:

The LHM3401 or LMH5401 would be a good suitable choice for DC coupled applications.

Thank you for the information.
Do you have a recommended circuit for DC coupling?

Rob Reeder said:

We can help you with that but we need more information/requirements to go.

I would appreciate it if you could tell me what kind of information you need.

Thanks,

Conor

Hi Conor,

I would review page 26/27 in the LMH5401 datasheet, here these is a good DC coupling reference circuit.

From there we would need to know what BW you need to setup the anti-aliasing filter. This could be as simple as an RC lowpass filter if you don't plan to pass much else other than DC.

So, we would need to know, BW, for starters.

Regards,

Rob

Hi, Rob

If possible, we would like to consider a power supply of ±15V. Isn't THS4151 suitable for DC coupling?

The circuit assumes an input signal of ±3.3V 1MHz, but DC input is also possible, so I would like to use DC coupling.

I simulated with PSpice, so please let me know if you have any observations or advice.

AnalogInput.pdf

Thanks,

Conor

Hi Conor,

This should work, I would try to get the output common mode voltage as close as possible to what the ADC requires, which is 1.5V.

I will forward this post to our HSAmps team to review. I want to make sure I didn't miss anything.

Thanks,

Rob