I'm trying to build a LM3550 (
https://www.ti.com/product/LM3550) based LED flash circuit. Note the datasheet contains dates from 2009...
The datasheet requires a small size supercapacitor, of size around 0.5-1 farad (for reasonable flash duration of about 30ms, and reasonable charge time of about 3 seconds), and ~50 mR ESR (to minimise voltage headroom required for ohmic losses at currents around 5A).
However, the referenced supercap from the datasheet (TDK EDLC272020-501-2F-50) is obsolete according to both TDK and digikey, however I can find no non-obsolete part with similar specs.
It seems that supercaps with the desired ESR are now 10 F+. This means that both charging time, and therefore battery charge wastage, would increase in order to achieve desired flash performance.
So where did parts like this go?
Are they all being bought up by renewable energy projects before they hit distributors like digikey?
Did the manufacturers all pursue high-capacity supercaps, as there's no market for low-capacity, low-ESR supercaps?
Are we meant to use other technologies, like lipo batteries or supersized electrolytic capacitors?
Or am I not looking hard enough?
I did manage to find a ~50mF electrolytic capacitor that might just work for my purposes but it's huge and doesn't provide an ESR figure, but I'd like to see if there's a better option.
Thanks for the help!