R
rob
Hi to all.
I am building a 12 to 19V @4A convertor using an uc3843 controller
chip.
I am using an inductor , not a xfmr , so there is no isolation. The
frequency
is 300khz.
I was wondering how to calculate the compensation components , in and
around the feedback cct.Looking on the internet at various ccts using
this chip
I have seen wildly differing values. The resistor / cap combination
from the output of the error amp to the - input is 100k // 100p at the
moment. I have seen values from 220k// 100n . (yes , that is nano)
At the moment the convertor is "working" , but it is making a high
frequency
singing / hissing noise , which it should not do.
Any help would be appreciated.
Cheers
Rob
I am building a 12 to 19V @4A convertor using an uc3843 controller
chip.
I am using an inductor , not a xfmr , so there is no isolation. The
frequency
is 300khz.
I was wondering how to calculate the compensation components , in and
around the feedback cct.Looking on the internet at various ccts using
this chip
I have seen wildly differing values. The resistor / cap combination
from the output of the error amp to the - input is 100k // 100p at the
moment. I have seen values from 220k// 100n . (yes , that is nano)
At the moment the convertor is "working" , but it is making a high
frequency
singing / hissing noise , which it should not do.
Any help would be appreciated.
Cheers
Rob