Sure, there are better voltage regulators now but the µA723 has been used in virtually every fixed voltage open frame linear power supply manufactured since it was introduced in 1968. I found the datasheet and the first application note some time ago along with some pretty gold parts. It only seemed fitting to celebrate its' birthday.
There's an interesting thread on the µA723 at the EEV blog. https://www.eevblog.com/forum/projects/ ... -pictures/
Two of the µA723 are Fairchild, the third was made by Microsytems International.
µA723 Data sheet, September 1968: https://proaudiodesignforum.com/images/ ... d_1968.pdf
µA723 Application Note, 1968: https://proaudiodesignforum.com/images/ ... r_1968.pdf
My brother wrote the pricing in 1970-ish dollars on the datasheet. 1-24 parts was $6.50. DIP was 50 cents more.
Adjusted for inflation that's $51.17 in 2023 dollars.
Mouser currently has the µA723CN for 95 cents.