A magnetic power and communication interface for a CMOS integrated circuit

Bulk CMOS integrated circuits which receive power and perform all I/O functions exclusively by means of inductive coupling are discussed. Both layers of metal in a conventional two-level-metal 3μm p-well technology were used to construct on-chip planar coils for sensing and perturbing externally generated magnetic fields in the 100 kHz to 10 MHz regime. The optimal design uses few, rather than many, coil turns operated at high frequency. The power delivered to one test chip was 0.9 mW at 3 V, while a second test chip demonstrated inductive low-power bidirectional communication