Interleaved SMPS's for 850W output is OK?

[Flyback]

Hello,
We wish to interleave four LT3791-1 based boost converters, each with a switching frequency of 222KHz.
The switching of each will be 90 degrees phase shifted.
(so the overall switching ripple in the input and output caps will be at 888KHz)
The schematic and LTspice simulation is attached.
Is there any problem with this (somewhat unusual) SMPS configuration?

The overall spec is
vin=28v
vout=34v
iout = 25Amps (total of all four stages)


LT3791-1 datasheet
https://cds.linear.com/docs/en/datasheet/37911fa.pdf

 

[ronsimpson]

How did you phase shift by 90?

 

[crutschow]

How are you generating the 90 degree phase shift?

Is there a way to insure that the load is shared equally by all four converters?

 

[ronsimpson]

Load sharing: I have seen one error amp used and all the COMP pins tied together. That way all the duty cycles are about the same.

 

[Flyback]

yes that's right....the quadrature phasing of the switching is done by alternately pulsing the sync pins of each converter......these pulses are obtained by pushing a pulse stream which is high,low,low,low through a 4way SIPO shift register and feeding each of the streams to one of the converters.

 

[crutschow]

Here's another version of a 4-phase converter.