Comment by ACCount37
7 days ago
My sleeper pick for a design like this was JL700N series. Intended for cheap TWS, ultra high integration. 3x3mm QFN20 package, and in it: BLE, USB, can be powered off 5v or 3.3v, built in battery support complete with a charger, almost no passives required. SDK was a bitch though.
There are more pieces like this in "wearables" market now, things like "SmartBond" series. But for a while, weird off-label pieces like this wore the integration crown.
Wearable MCU is sometime stupidly good. Recently i learned that the new Pepple watch use SF32lb55. It has dual mode bluetooth with LE Audio, all the fancy like pmic, battery charger, usb, 2.5D GPU etc, it also has insanely large memory(16MB flash/8MB PSRAM on some packages). The whole MCU costs like $3.
If you dive into even more niche, NDA-Only MCU, We have BES2700 MCU, which is even better