T
treez
Guest
Hello,
Compared to doing just a simple, standard full bridge converter, what might be the problems in development of a 850W phase shift full bridge smps?, where..
vin = 18to 32v
vout = 34v
Iout = 25 amp max
I mean, would we need a sectioned bobbin for the transformer?, (so that we get an exact amount of leakage inductance?)
Can we do a phase shift full bridge smps with a tightly wound transformer with very very little leakage (eg K = 0.995)?
Can we expect resonant operation over the full input voltage range?
Do we still need to have a primary current sense transformer?
What if it goes into discontinuous mode at light load?
What if our leakage inductance is loosely toleranced, and varies widely from unit to unit? (say by 30%)
Do we still need snubbers across the secondary diodes?
Is the off state voltage across the primary fets and secondary diodes higher than in an equivalent power plain full bridge converter?
Are there higher circulating currents in the transformer due to the resonant operation (when compared to a plain full bridge converter)?
Does the phase shift full bridge get rid of fet switching losses at turn off and turn on?
The LTC1922-1 is a phase shift full bridge controller, and on page 20 of its datasheet, it states how ringing between the secondary leakage inductance and the output capacitance of the secondary side sync fets can produce serios overvoltages on those fets...surely this is a great disadvantage of phase shift full bridge topology?...i.e., the fact that one has more secondary snubber losses due to the need to damp the ringing between the enhanced leakage and the secondary sync fet capacitance?
LTC1922-1 datasheet...
http://cds.linear.com/docs/en/datasheet/1922f.pdf
Compared to doing just a simple, standard full bridge converter, what might be the problems in development of a 850W phase shift full bridge smps?, where..
vin = 18to 32v
vout = 34v
Iout = 25 amp max
I mean, would we need a sectioned bobbin for the transformer?, (so that we get an exact amount of leakage inductance?)
Can we do a phase shift full bridge smps with a tightly wound transformer with very very little leakage (eg K = 0.995)?
Can we expect resonant operation over the full input voltage range?
Do we still need to have a primary current sense transformer?
What if it goes into discontinuous mode at light load?
What if our leakage inductance is loosely toleranced, and varies widely from unit to unit? (say by 30%)
Do we still need snubbers across the secondary diodes?
Is the off state voltage across the primary fets and secondary diodes higher than in an equivalent power plain full bridge converter?
Are there higher circulating currents in the transformer due to the resonant operation (when compared to a plain full bridge converter)?
Does the phase shift full bridge get rid of fet switching losses at turn off and turn on?
The LTC1922-1 is a phase shift full bridge controller, and on page 20 of its datasheet, it states how ringing between the secondary leakage inductance and the output capacitance of the secondary side sync fets can produce serios overvoltages on those fets...surely this is a great disadvantage of phase shift full bridge topology?...i.e., the fact that one has more secondary snubber losses due to the need to damp the ringing between the enhanced leakage and the secondary sync fet capacitance?
LTC1922-1 datasheet...
http://cds.linear.com/docs/en/datasheet/1922f.pdf
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