面向助听器应用的低功耗自动增益控制环路

A Low Power Automatic Gain Control Loop for Hearing Aid Device

自动增益控制环路是由可变增益放大器和负反馈回路构成的闭环系统,被广泛应用于助听器、磁盘驱动电路及各类无线通信电路。采用SMIC 0.13μm 1P8MCMOS工艺,设计了一款用于助听器SOC的低功耗自动增益控制环路。该电路采用数字反馈回路进行增益控制。后仿真结果表明,在1V电源电压下,输入信号为8kHz,输出信号峰峰值为126mV时,电路的无杂散动态范围为68.415dB,总谐波失真为68.397dB,整体功耗为290μW,满足助听器SOC的应用需求。

A low power automatic gain control loop for hearing aid device was implemented in SMIC＇s 0. 13 μm 1PSM CMOS process, in which digital feedback loop was adopted for gain control. Post-layout simulation showed that, when operating at 1 V supply voltage, the circuit had an SFDR of 68. 415 dB and a THI） of 68. 397 dB for 8 kHz input frequency and 126 mV （Vp-p） output, and its total power was 290 μW, meeting requirements of hearing aid SOC.