LM5143A-Q1: How to calculate the input Impedance

Hello EricLee,

Thank you for your response.

I found this equation and the example section in the document. But I am confused due to some mismatches I found in it.

These values do not match with the the circuit shown in page 12

Can you please help me to understand how these values taken for output inductor and input capacitance.

Also please help me on how to choose the following parameters.

Cross over frequency of the switching power supply:

Fcross := 32kHz

Cut off frequency of the input filter:

fc := 5kHz

Maximum input impedance of the power supply:

Rin := 25⋅ohm

Thanks

Jishnu

Hi EricLee,

Thank you for your response.

Can I assume the Duty cycle as Vout/Vin ?

Also can you please check on the Inductor and output capacitor as I mentioned in previous query?

Hello EricLee,

Thanks again. 

I have one more confusion. I understood the equation you suggested 

For LM5143 we have 2 outputs. In that case, can we use the same equation since it uses parameters of one output only. Otherwise how can we calculate the impedance of the multiphase converter? Is there any other way?

Thanks

Jishnu

Hello EricLee,

Thank you for your support, It was useful for me