Run 2 (or 3) separate ac analyses: One with signal only (no EMI on pwr supply), another one (or 2) with your selected EMI configurations (the GSM one, or your battery charge variations) on the power supply, with signal input (AC) grounded.
PSRR value = (ac signal value on output) / (ac signal value on pwr supply) , usually expressed in dB (negative value, then, because it represents a rejection ratio).
Run 2 (or 3) separate ac analyses: One with signal only (no EMI on pwr supply), another one (or 2) with your selected EMI configurations (the GSM one, or your battery charge variations) on the power supply, with signal input (AC) grounded.
In my case AC analysis are useless because the whole circuit is strongly non-linear. I belive that what you said is valid only for linear circuits. I need to extract th PSRR value from a transient simulation. That's the only way I will have accurate results.
You say "with signal input (AC) grounded". If I do that there will be no switching activity in my Class D which is completely different of having the circuit working normally.
PSRR value = (ac signal value on output) / (ac signal value on pwr supply) , usually expressed in dB (negative value, then, because it represents a rejection ratio).
In my case AC analysis are useless because the whole circuit is strongly non-linear. I belive that what you said is valid only for linear circuits. I need to extract th PSRR value from a transient simulation. That's the only way I will have accurate results.
You say "with signal input (AC) grounded". If I do that there will be no switching activity in my Class D which is completely different of having the circuit working normally.
Right; I just forgot this is Class D, sorry! Don't know if a PAC analysis (with your non-autonomous switching scheme) could help? Usually, PAC analysis is used for a single frequency (sinus) operation.
erikl said:
PSRR value = (ac signal value on output) / (ac signal value on pwr supply) , usually expressed in dB (negative value, then, because it represents a rejection ratio).