{'fraction_non_alphanumeric': 0.041666666666666664, 'fraction_numerical': 0.029914529914529916, 'mean_word_length': 4.783950617283951, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A Two-Stage Time-Division Multiplexing AFE with Input Impedance Boosting DDA for EEG Signal Acquisition

This paper presents a two-stage time-division multiplexing analog front-end (TDMAFE) for multi-channel EEG signal acquisition. A four-channel synchronous TDM technology is proposed, which eliminates the mismatch among the four-channel signals. An impedance-boosted chopper based on differential difference amplifier (DDA) is proposed to increase input impedance. And an improved low-noise digitally-controlled DC servo loop (DCDSL) is proposed to eliminate DC offset. Designed in 0.18μm CMOS process, the entire AFE occupies 1.2mm2 area and consumes 30.6μW from 1.2V supply voltage. The post-simulation shows that the gain range of the AFE is 34-60dB. The range of the input offset cancellation is ±300mV. The equivalent input impedance is boosted to 1.6GΩ. The equivalent integrated noise is 1.66μVrms over the range of 0.1~100Hz.