ChrisP58,
I was / am aware of these issues. I am not sure what the minimum level is, as it is stated as DC. Ripple current for each DC link will split depending on how many there are and their values.
Ronv,
I should have put in there that it's 12V out of the 2675.
Some other info:
I have my webench sim for the switcher set to 20-40V input. I've used LTSpice to determine that i'll need 470uF to keep the voltage input between 20 and 40VDC. Now, that leaves a lot to be desired, because the webench sim is for DC, and I've got a spikey 100-120Hz 20-40V input out of the rectifier. The transient analysis output from the webench has a timescale too short for what I'm looking at, so it's not too helpful.
Anyway, I've also got the option to cut a 1" x 1" section out of the pcb, and lay an axial cap or two across the gap, thereby doubling my available height. When doing that, or doing what you are talking about, I run into area issues. My working area for thd or smt without the cutout and thereby putting me back into the original height requirement is about 1" x 1.5"
The best i've come up with is 2x330uF Axials, and I end up calculating the ripple @ 0.645A through each. I've found the TVX1J331MCD cap at
https://www.electro-tech-online.com/custompdfs/2013/07/e-vx-30194.pdf
which has a ripple rating of 650mA @ 120Hz, but no derating for 100Hz. (this thing needs to run on both 50 and 60Hz)
Plus, that gives me about 5mA of margin, which is too close for my tastes.