The circuit is a 52kHz simple switcher (LM2575HVT-5.0) The current demand is 150mA (min), and 750mA (max possible), with normal be ing about 220 mA (upwards of 95% of the time).
The input voltage is about 50 volts (it's really a stack of four 12-volt ba tteries under charge, but I bleed off a little so as not to run right up to the part's max voltage limit).
Anyway, the datasheet calls for a 100 uF aluminum electrolytic cap on the i nput. My problem is I put a 330 uF, 100-Volt, 3.5mm cap lead spacing (footprint) on the through-hole PCB. Classic case of the BOM not matching the footprin t.
I would like to have at least a 100-volt rated cap. CHIME IN IF YOU THINK I COULD LIVE WITH LESS THAN THAT...
About the closest I can find and still "fit" the existing board is an 80-vo lt, 62uF cap. Any chance that will work long term? I'm trying to avoid su per-height caps. I have the vertical space, but it would stick out high eno ugh off the board to be a concern.
We're only talking 50 boards, not yet stuffed. I guess I could remake them ?? Ughh. Folding the cap over isn't really an option, though there is ple nty of space to do so.
I guess another option might be to parallel a PAIR of smaller caps, one on the component side, and another on the solder side. (??)