Integrated 16-Channel Neural Recording Circuit with SPI Interface and Error Correction Code in 130 nm CMOS Technology

In the research of neural diseases like epilepsy and schizophrenia genetic mouse models play a very important role. Dysfunctions during early brain development might cause these diseases. The analysis of the brain signals is the key to understand this process and develop treatments. To enable the acquisition of brain signals from neonatal mice, an integrated circuit for neural recording is presented. It is minimized for low area consumption and can be placed in a miniaturized system on the head of the mouse. It is intended to acquire the local field and action potentials from the brain. 16 analog input channels are implemented. The biomedical signals are amplified with analog re-amplifiers. Two parallel structures of 8:1 multiplexer, post-amplifier and ADC are implemented to digitize the signals. The post-amplifier has programmable gain and high driving capability. The ADC is implemented as a 10 bit SAR ADC. Digital SPI interfacing is used to reduce the number of transmission lines. Reed Solomon Error Correction Coding has been implemented to enable error correction. The mixed-signal integrated circuit has been successfully implemented in a 130 nm CMOS technology. It is optimized for low area consumption; the channel density is approximately 10 channels/mm²