Quartz oscillator in complementary m.o.s. technology

A short mathematical method is developed to obtain the drain¿source current expression at low voltage of an m.o.s. transistor, and therefore the gain of a complementary m.o.s. invertor. Input/output transfer characteristics are compared with computed theoretical results. A variant of the c.m.o.s. invertor, the passive-charge invertor, gives the best results for supply voltage. Another variant, the mixed-charge invertor, is the most advantageous from the point of view of frequency change with temperature and supply voltage.