一种基于反相器的音频应用低功耗Sigma-Delta模数转换器  

A Low Power Inverter-Based Sigma-Delta ADC for Audio Applications

作　　者：柯强[1,2] 卫宝跃[1,2] 梁帅[1,2] 刘昱[1,2] 张海英[1,2] 

机构地区：[1]中国科学院微电子研究所,北京100029 [2]新一代通信射频芯片技术北京市重点实验室,北京100029

出　　处：《微电子学与计算机》2016年第8期24-28,共5页Microelectronics & Computer

摘　　要：为实现音频应用低功耗Sigma-Delta模数转换器的设计,采用基于反相器的设计方法.模数转换器中Sigma-Delta调制器采用单环三阶前馈结构,以及基于反相器的开关电容积分器设计,并采用恒定跨导偏置LDO精确调整反相器的工作点,提高电路稳定性.该Sigma-Delta调制器采用SMIC 0.18μm CMOS工艺,在采样频率6.144 MHz下,24kHz音频信号带宽内,信噪失真比(SNDR)为91.5dB,动态范围(DR)为96dB,工作电源电压为1.3V,整体功耗为0.48mW,满足高性能低功耗的要求.An inverter-based design technique is applied to accomplish a low power Sigma-Delta analog-to-digital converter （ADC） for audio applications. The Sigma-Delta modulator of the ADC adopts three order feedforward structure. The modulator is based on inverter-based switched-capacitor integrator. To increase the robust of the modulator, a constant gm bias LDO is used to regulate the inverter bias point. The Sigma-Delta modulator is implemented in SMIC 0.18μm CMOS process. The simulation results of the Sigma-Delta modulator achieve 91.5 dB signal to noise and distortion ratio （SNDR）, 96 dB dynamic range （DR） over 24 kHz audio band with 6. 144 MHz sampling frequency and it consumes 0.48 mW power with 1.3 V supply voltage. The modulator is suitable for high performance and low power applications.

关 键 词：音频模数转换器 Sigma—Delta调制器 低功耗 基于反相器的开关电容电路 

分 类 号：TN4[电子电信—微电子学与固体电子学]