A linear power amplifier is used, which is mainly made up of an operation amplifier and a Darlington transistor because of the low power range. 由于是处在小功率范围，功率放大器采用的是线性放大器，由一个运算放大器和一个达林顿管构成了功率放大器的主体。
In addition to the aforementioned circuit implementations, this dissertation proposes a novel method for increasing linear output power under the same VDD and loads. 除了上述的单晶片音频放大器实现之外，本论文同时提出一个创新的方法使得数位放大器在相同电压与负载下可以延伸线性输出功率范围。
