A Wireless Power and Data Transfer IC for Neural Prostheses Using a Single Inductive Link With Frequency-Splitting Characteristic

Simultaneous High-Efficiency Power Delivery and Energy-Efficient Forward Data Transmission Over Single Inductive Link

“…For power transmission, we obtained the FOM value comparable to that in [17], which is 20.94 and it is 38.7 times compared to prior arts using a single inductive link [17]. For data transmission, our link also has sufficient bandwidth to support high DR communication.…”

“…where r refers to coil radius and d refers to the separation distance between the two coils, and θ is the angle between the planes of the coils. The k is larger than 0.3 in [17], which limits the separation distance of the coil to 5mm. To make the distance range of the link wider, k is not very large in our design.…”

“…As shown in Fig. 6, a three-stage injection-locked ring oscillator with low power consumption and a wide injection-locked range is designed [17], [29]. The free oscillation current of each RO stage is I osc = 1µA.…”

“…Some state-of-theart works [10], [11], [12] have been reported using multiple links for SWPDT design, unfortunately, these designs are complex to implement and suffer from crosstalk between the different links [10]. Therefore, for the requirement of simpler design and smaller size of IMDs, it is necessary to design SWPDT over a single inductive link and to address this trade-off at the same time [13], [14], [15], [16], [17].…”

“…The SWPDT methods presented above are based on the resonant frequency point of the inductive link and they operate in the weakly coupled region [22], [23]. In recent years, some SWPDT systems based on inductive links with frequency-splitting characteristics have been proven to be feasible and have demonstrated excellent performance [16], [17]. However, the point-point FSK (PP-FSK) in [16] makes the PTE degraded and its demodulation circuit is complex; the flat region FSK (FR-FSK) in [17] solves the trade-off between PTE and DR, but the system has some problems: (1) the system operation is limited by the close coil separation distance(5mm).…”