摘要
设计了一种低失真、高电源抑制比的D类音频功率放大器.该功率放大器采用幅值为1 V,频率为300kHz且斜边失真小于0.1%的双边三角波作为载波的PWM调制方式,大大降低了D类音频功率放大器的总谐波失真度,并提高了系统的电源抑制比.仿真测试结果表明:在5 V的电源电压下驱动4Ω负载,可提供2 W的额定输出功率,且典型总谐波失真小于0.08%,在频率为217 Hz时电源抑制比可达到77 dB.在保证D类音频功率放大器高效率输出的同时,也保证了输出信号较小的失真度和较强的抗电源干扰能力.
A class D power amplifier with low total harmonic distortion （THD） and high power supply rejection rate （PSRR） was presented, in which pulse width modulation （PWM）, with double-sided sawtooth carrier of amplitude of 1 V, frequency of 300 kHz and nonlinearity of 0.1%, was used to decrease THD and improve PSRR. According to the simulation, it could supply an output power of 2 W at a supply voltage of 5 V with a 4 Ω load, the THD was less than 0.08% and PSRR was 77 dB at 217 Hz. The results indicated the high efficiency output with strong power supply rejection.
出处
《华中科技大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2008年第8期52-55,共4页
Journal of Huazhong University of Science and Technology(Natural Science Edition)
关键词
D类音频功率放大器
PWM调制
谐波失真
电源抑制比
class D audio power amplifier
pulse width modulation
total harmonic distortion
power supply rejection rate
