I. INTRODUCTION
With the continuous advancement of CMOS technology, neural recording circuits have developed rapidly towards digitization, compactness, and low power consumption. The early neural recording systems were mainly composed of instrument amplifiers (IA) and low resolution analog-to-digital converter (ADC) [1] - [3]. IA had the characteristics of high gain and low input noise, but the high gain of amplifiers easily saturate the stimulation artifacts, thus this approach only supports acquisition scenarios without artifacts. In recent years, a novel approach of directly collect neural signals with high resolution and low power ADC has been proposed, which can accurately collect neural signals and stimulation artifacts [4] - [5]. The structure of the two solutions is shown in Figure 1.