[SOLVED] MP33063 Efficiency, Schottky Diode and Inductor

[ivign]

Hi

I have a few questions in designing boost converter for MC33063.

a) Is there a way to calculate the efficiency with formulas?

b) My Ipk is around 1.36A, how does this current affect my selection of Schottky diode and Inductor?
Is 1N5819 alright for this case? Since the average forward current is only at around 1A for 1N5819?
Output voltage at 31V.

Please help.

Thanks

 

[ea.arun]

i think the 1.36A mentioned is the current flowing through the internal switch from the input supply.....the curent flowing through the output capacitor(also through the diode) will be still less since the voltage is higher(boost application).....and during the switch-off time the surge current occurs for a very short time......so i feel you can use the 1N5819 in this application......
but this current is going to flow through the inductor which must have the saturation current above this(say 30% above)....

As far as efficiency is concerned calculate the output power required and losses from the input(due to diode drop,loss across the switch(static and dynamic),loss across the sense resistor etc) and get the ratio.....here are some application notes which will guide you.....

**broken link removed**
https://users.ece.gatech.edu/rincon-mora/publicat/trade_jrnls/pmdl_0806_boost_losses.pdf