6. How to design driving circuit for micro-speakers?
Driving circuits serve the purpose of amplifying audio signal and inputting it into micro-speakers. Typically micro-speakers are complemented by one of the two following amplifier circuit. First, clients use AB-class amplifier since it’s easier to design and cheaper, yet it’s not efficient and produces excess heat; To mitigate those problems, most of the clients now chooses D-class amplifier, which uses PWM to send audio signal into the micro-speaker. The advantage of D-class amplifier is its high efficiency and low heat emission, yet is suffers from EMI problems.