cupoftea
Advanced Member level 6
Hi,
The attached, LTspice and jpeg is a Buck 24vin, 15vout 3Aout.
The hi side drive is just done with a linear regulator.
The hi side linear reg is needed as there is no low side fet to turn on and get the bootstrap cap charged.
(A low side FET isnt needed.)
Sync Buck is to be avoided if poss, since you always need more expense like picking FETs with (crss <0.05 * Ciss) so that you dont get spurious turn on.
Do you believe this is ok?
You might say just buy a non sync buck chip, but the choice of such on the market is ridiculously poor.
There's that dreadful LM2XXX thing that works at a fixed 50kHz or so...no thanks....always out of stock anyway....and you always have to put up with its internal fixed peak current level..whether you like it or not.
You need to turn a sync buck chip into a Non sync buck chip as attached, would you agree?
The attached, LTspice and jpeg is a Buck 24vin, 15vout 3Aout.
The hi side drive is just done with a linear regulator.
The hi side linear reg is needed as there is no low side fet to turn on and get the bootstrap cap charged.
(A low side FET isnt needed.)
Sync Buck is to be avoided if poss, since you always need more expense like picking FETs with (crss <0.05 * Ciss) so that you dont get spurious turn on.
Do you believe this is ok?
You might say just buy a non sync buck chip, but the choice of such on the market is ridiculously poor.
There's that dreadful LM2XXX thing that works at a fixed 50kHz or so...no thanks....always out of stock anyway....and you always have to put up with its internal fixed peak current level..whether you like it or not.
You need to turn a sync buck chip into a Non sync buck chip as attached, would you agree?
