Efficient Earbud Charging is All About Keeping a Cool Head

By: Josh Fankhauser, Michael Jackson


True wireless earbuds commonly use three (or more) pins to interface with their charging case, for data and power transfer. Extra pins need more space while also causing a reliability concern. Additionally, a fixed voltage is commonly used during earbud battery charging, an approach that can cause unwanted heating. In this design solution, we examine the shortcomings of these approaches in more detail before presenting a composite approach that uses two ICs to address these concerns.