Hi! I need to choose an SMD bulk capacitor to put in my PCB in the power supply line. I used the following formula to calculate it:
Cbulk (min) = ( D*(1-D)*Iout / (Vripple*FreqSwitch) ) with D = Vo / Vin * efficiency
Now I have to choose which SMD capacitor to use and I am faced with the choice of two parameters: ESR and rated ripple current.
In this case (if I am not mistaken) I choose ESR as small as possible ( because P=R * I^2 ) ... what about Iripple?
In the lessons I am following, the following sentence is stated and a high Iripple is chosen:
"When the transient current exceeded the ripple current value, the capacitor current will saturate and it can cause heating, yes heating depends on its totally resistive component of it"
Can you explain this statement to me? And especially whether in this application the ripple current should be taken minimum or maximum :/
Thanks
Cbulk (min) = ( D*(1-D)*Iout / (Vripple*FreqSwitch) ) with D = Vo / Vin * efficiency
Now I have to choose which SMD capacitor to use and I am faced with the choice of two parameters: ESR and rated ripple current.
In this case (if I am not mistaken) I choose ESR as small as possible ( because P=R * I^2 ) ... what about Iripple?
In the lessons I am following, the following sentence is stated and a high Iripple is chosen:
"When the transient current exceeded the ripple current value, the capacitor current will saturate and it can cause heating, yes heating depends on its totally resistive component of it"
Can you explain this statement to me? And especially whether in this application the ripple current should be taken minimum or maximum :/
Thanks