Towards an inductively coupled power/data link for bondpad-less silicon chips

This paper explores the concept of developing a bondpad-less fully-integrated inductive link for power/data transfer between a CMOS Integrated Circuit (IC) and a PCB. A key feature of the implemented system is that it requires no off-chip components. The proposed chip uses a standard 0.35 μm process and occupies an area of 2.5 mm × 2.5 mm and an on-chip inductor occupies an area of 1.5 mm × 1.5 mm. At 900 MHz, 9 mW was designed to be provided to the chip (up to 22.5 mW with a total efficiency of 5 %). Binary Phase Shift Keying (BPSK) and Load shift keying (LSK) are used for the the PCB-to-chip and chip-to-PCB link respectively for half-duplex communication. An Injection-Locked-Oscillator-based BPSK demodulator is implemented on-chip to save power. The maximum data rate for the PCB-to-chip link is lOMb/s. The estimated area of the circuitry is only 2 mm² which is 32 % of the total chip area.