LTC5586 : Anti-alias Lowpass Filter

Thanks you for your response. I have an another question about ADC input impedance.

Into simulation, there is 50ohms  resistor which is ADC input. Input impedance is usualy several kilo ohms so why there is this 50 ohms resistor ?

Have you got an application note to compute anti-alias asymmetrical impedance low-pass filter ?

I don't understand how low-pass filter are calculated ?

Thanks

BP_FRANCE

Thanks you for your response. I have an another question about ADC input impedance.

Into simulation, there is 50ohms  resistor which is ADC input. Input impedance is usualy several kilo ohms so why there is this 50 ohms resistor ?

Have you got an application note to compute anti-alias asymmetrical impedance low-pass filter ?

I don't understand how low-pass filter are calculated ?

Thanks

BP_FRANCE

Many modern highspeed pipeline ADCs have buffered input with 100 to 400 ohm input impedance. In the LTspice example, we showed an ADC with 100 ohm differential input impedance. Even if you use an un-buffered ADC, it is recommended to double-terminate the anti-alias filter.

The LTC5585 datasheet gives a tutorial on unequal termination filter design in its Appendix section.

Filter designs for ADCs can be quite complex and tricky. I would suggest that you post in the ADC section to get support from our ADC experts.