低电压下高效音频功率放大器的仿真与分析

当对非线性失真有一定要求时,低频功率放大器的实际最大输出功率和效率均低于理想状态时的理论分析值,特别在电源电压较低时,其影响更为明显.依据自举电路可扩大放大器的动态输出范围的原理,提出了一种双自举电路的OCL低功率放大器,以提高电路的输出电压,从而提高最大输出功率和效率.仿真结果表明：电源电压较低时,在非线性失真系数低于2%的条件下,与OCL电路相比,双自举OCL电路的最大输出电压提高了约1倍,最大不失真输出功率提高了约3倍,效率提高了近20%.

Simulation and Analysis of High Efficiency Audio Power Amplifier Supplied With Low Voltage

With a certain requirement for non-linear distortion, the available maximum output power of the LF power amplifier and its efficiency are both below the theoretical value of the ideal state, and this impact is more serious, especially in the case of lower source voltage, On the basis of bootstrap circuits enlarging the output dynamic range of the power amplifier, this paper puts forward an OCL LF power amplifier using dual-bootstrap circuits to boost the circuit＇s output voltage, thus improving the maximum output power and efficiency. Simulation results show that the maximum output voltage of the dual-bootstrap OCL circuit increases by one time, the maximum distortion-less output power by around three times and the efficiency by 20%, for the case where the source voltage is lower, and the non-linear distortion coefficient is less than 2%, compared to the OCL circuits.