Here's a Bubba oscillator that uses diodes to give a soft limit to control the amplitude of the oscillator and provide low distortion (better than a half percent at Vout in simulation). I also modified the circuit so that the left capacitor is in the feedback of the inverting stage and thus isn't loaded by the inverting stage as is typical.
The oscillation frequency is 1/(2\(\pi\)RC).
The DC loop gain must be slightly greater than 4 for oscillation to occur as is normal for the Bubba oscillator. This can be adjusted by R5 and R7 to compensate if a different R value is used to vary the frequency.
View attachment 337
View attachment 338
The oscillation frequency is 1/(2\(\pi\)RC).
The DC loop gain must be slightly greater than 4 for oscillation to occur as is normal for the Bubba oscillator. This can be adjusted by R5 and R7 to compensate if a different R value is used to vary the frequency.
View attachment 337
View attachment 338
