摘要
传统的模拟麦克风由于自身抗干扰能力差,很难满足新一代音频系统对输入端的要求,文章提出了一种用于数字麦克风的CT-SC Σ-Δ调制器技术,将CT积分器和SC积分器结合在一个Σ-Δ调制器中,可以与驻极体麦克风进行无缝连接,能够将麦克风产生模拟信号直接转换成后续数字设计平台所需的数字信号。测试结果表明,CT-SC Σ-Δ调制器动态范围达到88 dB,等效输入参考噪声为5μV,正常工作功耗为540μW,休眠模式下消耗电流不超过10μA;与传统模拟麦克风相比,CT-SC Σ-Δ调制器构成的数字麦克风可以提供更好的信噪比、更高的集成度、更低的功耗和更强的抗干扰能力。
A mixed CT-SC ∑-△ modulator was designed,which could be directly connected to electret microphone and convert analog signal into digital one. Measurement results showed that the CT-SC ∑-△ modulator had a dynamic range of 88 dB,an equivalent input referred noise of 5 μV, a typical power consumption of 540μW,and in standby mode,the current didn＇t exceed 10 μA. Compared with analog microphone, electret microphone with CT-SC ∑-△ modulator offers better SNR, higher integration,lower power consumption, and stronger immunity to system noise.
出处
《微电子学》
CAS
CSCD
北大核心
2009年第2期150-154,共5页
Microelectronics
