IEEE Trans Biomed Circuits Syst. 2010 Oct;4(5):295-300. doi: 10.1109/TBCAS.2010.2066272.
With the emerging interest in local field potentials (LFPs) as input signals for brain-machine interfaces, there is a need for integrated circuits capable of amplifying spikes and LFPs. A two-stage complementary metal-oxide semiconductor (CMOS) amplifier-filter has been implemented with 0.18-μm CMOS for simultaneous, multimodal recording of extracellular unit spikes and LFPs. For the frequency tuning and the reduction of the 1/f noise, it employs a switched-capacitor technique. The filter bandwidth is reconfigurable by using a different sampling clock frequency. The prototype amplifier has gains of 19.1 dB and 37.5 dB for low-pass only filter and cascaded filter, respectively. With a 100-kHz sampling frequency, the equivalent input noise spectral density is 38.8 nV/√Hz while the total power consumption is 69 μW with a 1.6-V supply, including clock generation and biasing occupying an area of 44 × 148 μm(2).
随着人们对局部场电位 (LFPs) 作为脑机接口输入信号的兴趣日益浓厚，需要能够放大尖峰和 LFPs 的集成电路。采用 0.18-μm CMOS 工艺实现了两级互补金属氧化物半导体 (CMOS) 放大器滤波器，用于同时记录细胞外单元尖峰和 LFPs 的多模态信号。为了进行频率调谐和降低 1/f 噪声，它采用了开关电容技术。通过使用不同的采样时钟频率，可以重新配置滤波器带宽。对于低通滤波器和级联滤波器，原型放大器的增益分别为 19.1 dB 和 37.5 dB。在 100 kHz 的采样频率下，等效输入噪声谱密度为 38.8 nV/√Hz，总功耗为 69 μW，电源为 1.6 V，包括时钟产生和偏置占用面积为 44×148 μm(2)。
