摘要
传声器集成电路将接收到的麦克风声音信号转换成电流信号,再由前置放大器放大成电压信号。通常,当声音信号很微弱时,放大器放大声音信号时也放大了噪声,造成被放大的声音信号的信噪比很低。对两种电路进行了仿真试验,比较了Claus前置放大器和Eduard CMOS前置放大器的噪声特点。采用0.18μm CMOS工艺进行仿真,分析了电路的噪声频谱密度,提出了一种改进型CMOS前置放大器,有效地改善了前置放大器的信噪比。
The microphone circuit converts voice signals received from microphone into current signals,which is then amplified by preamplifier and converted into a voltage signal.Typically,when the voice signal is weak,the amplifier also amplifies noise,which would result in a low SNR.Noise characteristics of Claus pre-amplifier and Eduard CMOS pre-amplifier circuits were compared and analyzed.Based on 0.18 μm CMOS process,a novel CMOS preamplifier with improved noise characteristics was proposed.Noise spectral density of the circuit was analyzed.Simulation results showed that signal-to-noise ratio of the proposed preamplifier was effectively improved.
出处
《微电子学》
CAS
CSCD
北大核心
2012年第2期150-153,共4页
Microelectronics
