100-Channel wireless neural recording system with 54-Mb/s data link and 40%-efficiency power link

For real-time monitoring of brain activities, a highdata-rate, low-power, and highly mobile neural recording system is desirable. This paper presents a complete chipset for a 100-channel wireless neural recording system, which consists of 3 ICs — a neural interface (NI) IC and a wireless power RX and data TX IC for an implant unit (IU), and a wireless data RX IC for an external head unit (EHU). With a dual S/H NI architecture and a burst-mode (BM) wideband (WB) FSK TX, the IU achieves a 100-channel recording and wireless transmission at 54.24Mb/s while consuming only 6.6mW. Using power coupling with optimal resonant load transformation and high-efficiency rectifier and LDO circuits, the whole wireless power link achieves 40% efficiency over 1cm distance with 0.5cm tissue in between. The EHU needs to transmit the RF power lower than 30mW to operate the IU. The EHU is implemented using a crystal-less BM WB FSK RX consuming only 14.4mW at 27.12Mb/s.