Hello,
In the (below) ‘coupled-inductor’ SEPIC converter schematic, why does the sizing of the “leakage” inductor (L4) , have no effect on the di/dt(ON), or the di (ON), of the FET current?
Whether the "leakage" inductor is 47uH , or 470nH, it makes no difference to the FET current.
Also, its a constant-off-time converter, but the sizing of the "Leakage" inductor makes no difference to the frequency of operation..why is this?
(L4 is an extra “leakage” inductor added in so as to reduce the input ripple current, and also to reduce the high frequency ringing currents which can occur in the coupled inductor if the leakage is not high enough in value)
SEPIC schematic:
http://i43.tinypic.com/28hg8i1.jpg
In the (below) ‘coupled-inductor’ SEPIC converter schematic, why does the sizing of the “leakage” inductor (L4) , have no effect on the di/dt(ON), or the di (ON), of the FET current?
Whether the "leakage" inductor is 47uH , or 470nH, it makes no difference to the FET current.
Also, its a constant-off-time converter, but the sizing of the "Leakage" inductor makes no difference to the frequency of operation..why is this?
(L4 is an extra “leakage” inductor added in so as to reduce the input ripple current, and also to reduce the high frequency ringing currents which can occur in the coupled inductor if the leakage is not high enough in value)
SEPIC schematic:
http://i43.tinypic.com/28hg8i1.jpg
