T
treez
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Hello,
We are doing an SMPS using the DCM3623T50M53C2T00 Vicor DCDC module.
We need to know what is the ripple current in the external output capacitors that we must fit.
Please either state it (ripple current), or comment on our method of derivation…..
PSU Spec:
……………………………………….
Vin is 33V
Vout is 48V
iout is 6A
Crossover frequency of DCM module is 20kHz.
The DCM module switches at ~750kHz
This DCM module comprises an internal output capacitor of 11uF with 0.222R of ESR.
There must be a minimum of 200uF of external output capacitance (max of 2000uF)
DCM module is a ZVS type
……………………………………………….
Method of derivation of ripple current in output capacitor bank………..
Page 14 of the DCM datasheet shows the output voltage ripple…this shows that its not a sinusoidal type converter like an LLC…..
…Therefore, it must be a Phase shift full bridge, since that is a ZVS topology.
As such, for our 6A of average output current, the worst case for ripple current would be a Boundary conduction mode triangle wave of 12A peak……….such a current waveform (as attached) has an RMS of 6.92A….this would give a output capacitor ripple current of 3.45A rms…would you agree?
(this is obviously the worst case, ie boundary conduction mode inductor current in the PSFB output inductor)
DCM3623T50M53C2T00 Vicor DCDC module datasheet
https://www.vicorpower.com/documents/datasheets/DCM3623x50M53C2yzz_ds.pdf
We are doing an SMPS using the DCM3623T50M53C2T00 Vicor DCDC module.
We need to know what is the ripple current in the external output capacitors that we must fit.
Please either state it (ripple current), or comment on our method of derivation…..
PSU Spec:
……………………………………….
Vin is 33V
Vout is 48V
iout is 6A
Crossover frequency of DCM module is 20kHz.
The DCM module switches at ~750kHz
This DCM module comprises an internal output capacitor of 11uF with 0.222R of ESR.
There must be a minimum of 200uF of external output capacitance (max of 2000uF)
DCM module is a ZVS type
……………………………………………….
Method of derivation of ripple current in output capacitor bank………..
Page 14 of the DCM datasheet shows the output voltage ripple…this shows that its not a sinusoidal type converter like an LLC…..
…Therefore, it must be a Phase shift full bridge, since that is a ZVS topology.
As such, for our 6A of average output current, the worst case for ripple current would be a Boundary conduction mode triangle wave of 12A peak……….such a current waveform (as attached) has an RMS of 6.92A….this would give a output capacitor ripple current of 3.45A rms…would you agree?
(this is obviously the worst case, ie boundary conduction mode inductor current in the PSFB output inductor)
DCM3623T50M53C2T00 Vicor DCDC module datasheet
https://www.vicorpower.com/documents/datasheets/DCM3623x50M53C2yzz_ds.pdf
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