Hi, Sougata

Thanks for the XLS sheet ...

TL431 is to consider like a Zener diode ... noise involved !!!

I always use a solid aluminium 10µF cap ( Alusol C 122 ) or tantalum cap ...

With a good 4.5 digits multimeter for trimming - and quality components - ... performance is to compare to MAX or AD best voltage refs ...

Not so bad, for such an oldie !!!

Alain