Low Resistance Integrated Toroidal Inductors for Power Management

5.6times5.6times0.5 mm³ integrated toroidal inductors with high L/R_DC ratio have been fabricated on Si substrates with microelectronics tools. The realization features thick layer Cu and Ni₈₀Fe₂₀ technologies. Impedance measurements have been performed up to 100 MHz. As a typical result, we show an inductor with L ~ 500 nH up to 10 MHz, R_DC ~ 110 mOmega. To our knowledge, it is the best compromise shown so far. This demonstrates the interest of such integrated inductors to replace discrete ferrite inductors for compact power modules for mobile communication circuits.