The simplest version of a ring oscillator using two inverters Iike the one shown in other circuits in this section has some problems. It is dependent on the voItage source and some deformatíons can be observed in the output signal - it is not perfectly square. The best performance of a ring oscillator using two inverters can be achieved with the configuration shown here. The added resistor avoids the RC network to be Ioaded by the clamping diodes inside the CMOS IC. The resistors and C1 determine the frequency.
Improved Two-lnverter Oscillator
