Vapes are probably made in enough quantity to warrant custom silicon. Then the mosfets and charge circuit could be on the same die. It could be mounted COB (black blob).
They could probably use a single 'microphone' (pressure sensor) and determine which setting based on a photodiode.
The PCB's could be replaced with a flex PCB which integrates the heating elements (Vegetable Glycerine boils at 290C, whereas Polyimide can do 400C for a short while). Construction of the whole device can then involve putting the PCB inside the injection moulding machine for the cavities, eliminating all assembly steps, joints and potential leaks, and reducing part count
Not when the MCUs might cost a penny and the other parts aren’t much more.
Putting high power electronics and analog into the same custom silicon as a custom digital logic is nontrivial. They’re made on different processes.
As long as you aren't interested in multi-Mhz operation, combining the rest at very low cost isn't too tricky.
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
Right, which they already get from a $0.01 MCU
Combining an MCU and multi-amp power transistors into the same package is expensive.
I mean relatively it absolutely is high power. The quiescent current on that thing has to be microamps…
It’s just funny because to me “high power” is hundreds or thousands of watts. Like an incandescent light bulb or a hair dryer. Or at least it was until I started tinkering with battery powered microcontrollers and doing math to realize exactly how long an 18650 might power a small strip of individually addressable LED’s…
“High power” is a very relative term :-)
Your estimate is 1-2 orders of magnitude too low. Small vapes pull a couple amps, as I understand it. Larger vapes can pull over 50-100W. The modded ones into the 200W range. These things can use more power than most CPUs for the brief moment they're on.
The power draw is so high that vape fans compare and review batteries to show which ones can sustain the most power output.
It's an unexpected boon for those of us who use batteries for other things: The vape craze has made more high current batteries available with a lot of user contributed test data.
The cheapest variety is a tiny PCB built into the microphone. It's three wires for the battery and heater, and that's it. Sometimes they include a cheap and nasty battery charger. All in a single grain of sand for almost free.
It has a separate magnetically attached battery / charging unit. I have to charge 5-6 times per "tank" that's attached. The battery side also has a mini-led display showing animations and battery / juice left so it's actually communicating with the tank side. A kit with battery and tank runs me about $25, but the tank alone is about $20. So they add $5 to cover the battery / charging component. It's a vice, but at least with this brand I'm not throwing away batteries weekly.