This paper presents a fast configurable automatic gain control (AGC) with strong focus on fast acting control and low power consumption. This AGC includes two paths, main amplification path and gain adjusting path. Using the gain adjusting path through an extra amplifier provides a way for tracking and comparing the input signal with four adjusted thresholds to be judged for selecting the appropriate gain value for main amplification path. This mechanism of gain control is done by reorganization of input level and changing the resistance of feedback in main amplification path to generate smooth variation gain, without any interruption or delay in signal flow through the variable gain amplifier. Moreover, in order to protect the user from intense transients in variations of the input signal level, output level of variable gain amplifier is directly monitored using optimum threshold to reduce the overall gain using feedback control mechanism. The minimum power is consumed by gain adjusting path has almost no considerable on power consumption, it greatly improves hearing quality. Meanwhile, using a large size PMOS differential pair at the input improved the noise performance. Proposed AGC designed and simulated in TSMC 130-nm CMOS process. The post layout simulation results the maximal SNR is 84.6 dB in 100 Hz–19.6 kHz band-width and the total consumption power of this AGC is 78 μW at 1 V supply voltage. In addition, its gain is varied smoothly between 20 to 57 dB. Achieved results demonstrate that designed AGC meet the requirement of analog front end of hearing aids.

本文提出了一种快速可配置的自动增益控制 (AGC)，重点关注快速动作控制和低功耗。该AGC包括两条路径，主放大路径和增益调整路径。使用通过额外放大器的增益调整路径提供了一种跟踪和比较输入信号与四个调整后的阈值的方法，以便判断为主放大路径选择合适的增益值。这种增益控制机制是通过重新组织输入电平和改变主放大路径中的反馈电阻来实现平滑变化的增益，而不会中断或延迟通过可变增益放大器的信号流。此外，为了保护用户免受输入信号电平变化的强烈瞬变，可变增益放大器的输出电平使用最佳阈值直接监控，以使用反馈控制机制降低整体增益。增益调整路径消耗的功率最小，对功耗几乎没有影响，大大提高了听力质量。同时，在输入端使用大尺寸 PMOS 差分对提高了噪声性能。建议的 AGC 在 TSMC 130-nm CMOS 工艺中设计和模拟。布局后仿真结果在 100 Hz–19.6 kHz 带宽内的最大 SNR 为 84.6 dB，在 1 V 电源电压下，该 AGC 的总功耗为 78 μW。此外，其增益在 20 至 57 dB 之间平滑变化。实现的结果表明设计的AGC满足助听器模拟前端的要求。