The MT6261 is actually a full feature-phone SoC (includes a GSM modem); a bit odd to see it in a smartwatch with no actual phone functionality.<p>This is basically a form of PWM. <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Pulse-width_modulation#Telecommunications" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Pulse-width_modulation#Telecom...</a>