title: A frequency shaping neural recorder with 3 pF input capacitance and 11 plus 4.5 bits dynamic range.
abstract: This paper presents a frequency-shaping (FS) neural recording architecture and its implementation in a 0.13 μ 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 μW/ch, of which 22 μW per FS amplifier, 24 μ W per buffer, 4 μ W per 11-bit successive approximation register analog-to-digital converter (SAR ADC). The input-referred noise for LFPs and extracellular spikes are 13 μ Vrms and 7 μVrms, 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.
authors: Jian
authors: J
authors: Xu
authors: Tong
authors: T
authors: Wu
authors: Wentai
authors: W
authors: Liu
authors: Zhi
authors: Z
authors: Yang
mesh_terms: D000465:Algorithms; D000669:Amplifiers, Electronic; D000818:Animals; D025802:Electric Capacitance; D004567:Electrodes, Implanted; D004867:Equipment Design / Q000295:instrumentation*; D051379:Mice; D009474:Neurons / Q000502:physiology*; D059629:Signal-To-Noise Ratio