A Frequency Shaping Neural Recorder With 3 pF Input Capacitance and 11 Plus 4.5 Bits Dynamic Range

作者：Xu Jian^*; Wu Tong; Liu Wentai; Yang Zhi

来源：IEEE Transactions on Biomedical Circuits and Systems, 2014, 8(4): 510-527.

DOI：10.1109/TBCAS.2013.2293821

• Frequency-shaping
• high impedance
• low-power low-noise design
• neural recorder
• wide data dynamic range

This paper presents a frequency-shaping (FS) neural recording architecture and its implementation in a 0.13 mu m CMOS process. Compared with its conventional counterpart, the proposed architecture inherently rejects electrode offset, increases input impedance 5-10 fold, compresses neural data dynamic range (DR) by 4.5-bit, simultaneously records local field potentials (LFPs) and extracellular spikes, and is more suitable for long-term recording experiments. Measured at a 40 kHz sampling clock and +/- 0.6 V supply, the recorder consumes 50 mu W/ch, of which 22 W per FS amplifier, 24 mu W per buffer, 4 mu W per 11-bit successive approximation register analog-to-digital converter (SAR ADC). The input-referred noise for LFPs and extracellular spikes are 13 mu Vrms and 7 mu Vrms, respectively, which are sufficient to achieve high-fidelity full-spectrum neural data. In addition, the designed recorder has a 3 pF input capacitance and allows "11 + 4.5"-bit neural data DR without system saturation, where the extra 4.5-bit owes to the FS technique. Its figure-of-merit (FOM) based on data DR reaches 36.0 fJ/conversion-step.

• 出版日期2014-8