Hello all, I wonder if there is a way to reduce supply sensitivity in an inverter based Ring oscillator ? Unfortunately I can't use a differential ring oscillator due to specs on power consumption.

Adding an LDO to provide the supply for it is by far the most common solution.

Running the ringosc off a regulated voltage and using weak pfet vs strong nfet reduces Supply bias dependence.

@Stefan Schippers Thanks for the answer but will the supply sensitivity still be reduced if I used a switching regulator like a charge pump with low output ripples instead of an LDO ?

I think simulation and testing the various solutions is the answer. It is important to specify what kind of sensitivity you are trying to minimize. Do you want to reduce dependence sesitivity on DC VCC value? OR what frequency components of the supply you want to be immune to?

@Stefan Schippers I want to minimize the change in oscillation frequency when changing DC supply voltage value.

Ok, so then using a regulated supply (using a bandgap reference for example) seems the best option.

You need to use something like this. But you will also need a level shifter, because the oscillator signal won't be rail-to-rail.