bq24030 evm why we need c7 ?

hi

Question 1 ( about C7):

It shows that C7 may be needed for programmed charging current less that 0.3A in bq24030's EVM user's guide

and I set charging current to be 75mA in my board,

but could you please tell me why we may need C7?

What is the C7 function in this circuit?

Question 2 ( about ISET1):

Here is the ISET1 waveform,

and it is not a DC voltage but seems like a sine waveform,

could anyone explain the reason for that?

Thank you very much for your support!

Br, Stone