摘要
设计实现了一种用于D类音频功率放大器中的自动增益控制系统,通过自动调整D类功放的增益,增大了D类音频功放的输入信号范围,避免了削波失真,使得D类音频功放能够在较宽信号输入范围内保持良好的总谐波失真（THD）,且不影响输出功率。该集成了自动增益控制系统的2.5 W单声道D类音频功放已经采用0.5μm CMOS工艺实现。测试表明,在电源电压5 V、功放增益18 dB、负载4Ω的条件下,该D类音频功放能够在0-2.3Vrms的信号输入范围内保持总谐波失真加噪声（THD＋N）〈2%,最大输出功率2.1 W。
An auto gain control system for Class D audio power amplifier applications is presented.The system can automatically adjust gain of the Class D audio power amplifier in order to expand the range of the input signal and avoid clipping without affecting the output power,so the Class D audio amplifier can keep good THD within the wide range of input signal.A Class D audio amplifier that integrated with the auto gain control system was implemented in 0.5 μm CMOS process.The measurement result shows that at 5 V power supply,18 dB gain and 4 Ω output load the amplifier can keep （THD＋N）2% with the max output power of 2.1 W within the input signal range of 0～2.3 Vrms.
出处
《半导体技术》
CAS
CSCD
北大核心
2010年第7期732-735,共4页
Semiconductor Technology
基金
浙江省科技厅重大科技专项基金(2006C14036)
关键词
D类音频功放
输入信号范围
自动增益控制
总谐波失真
Class D audio power amplifier
input signal range
auto gain control
total harmonic distortion
