Hi there.
I'm currently designing a 12VDC to 20VDC boost converter to feed a battery charger IC.
I've got some trouble prototyping it, let me explain :
I used WebBench to calculate the passive values and after building the circuit on a breadboard (I think it has something to do with it), i've got performance issues :
- I've got a ton of ripple on the output, it seems related with the comp loop, but i'm not very familiar with it.
- as long as the output stays below 80mA, everything seems "fine" (except for the 15vpp ripple...).
- under more load, the output voltage begins to drop, and around 150mA, the boost converter stops.
- randomly, the EN pin must be grounded and pulled high again to "restart" the boost converter.
I've already design "flawless" simple boost converters, without comp loop and so on, and i'm quite annoyed with this one. The switch pattern seems complicated (i can quite see it on the ripple).
We can't afford to spin countless prototyping boards, so my question is : is it breadboard related ? would it be ok on an full SMD board and a correct layout? Does these problems looks familiar for a "breadboard build" ?
About this EN pin, it seems to have a will of its own, as it is a "standalone circuit", i can't afford to switch it low/high every now and then. Is there a solution to prevent unexpected shutdowns ? Is it once again breadboard related ?
Thanks a lot and if you need more info, i'll provide as much as i can.
Julien
