Comment by londons_explore
14 hours ago
But you need very very little digital logic... The same kind of quantity to do the little power indicator LED's on a battery bank (which are charlieplexed btw), and thats done in the same ASIC that also has the 5V boost power supply (multi-amp gnd isolated n type mosfet) and charge circuitry involving voltage references and laser tuned comparators, and sometimes negotiates USB-C PD as well (needs an internal ROM). And the whole thing needs to be really cheap and with a standby current of uA's.
As long as you aren't interested in multi-Mhz operation, combining the rest at very low cost isn't too tricky.
If simplicity is the goal, then sure: Maybe spinning up a custom part can become useful.
But simplicity isn't always the goal. I have a throwaway vape here with a color LCD screen that plays full-motion animations.
To be sure, that's not necessary at all. But this functionality does exist, and people do buy them.
IIRC, they're said to use a 48MHz Cortex M0 part. More information here: https://github.com/ginbot86/ColorLCDVape-RE
> But you need very very little digital logic...
Right, which they already get from a $0.01 MCU
Combining an MCU and multi-amp power transistors into the same package is expensive.