An Inductively Tuned CMOS Astable Multivibrator

A new inductively tuned astable multivibrator is presented. The circuit is formed connecting a timing inductor across a composite nonlinear two-terminal, which is made up of two complementary pairs of cross-coupled MOS devices. The nonlinear differential equation describing the circuit is derived, which is solved for the oscillation period by quadrature. Exact expressions for both the amplitude and the period of the relaxation oscillation are found, as well as some useful approximations of them. Circuit simulations confirm the presence of a relaxation oscillation which is accurately predicted by the presented nonlinear analysis.