Yes I'm looking for a fully integrated solution.
I am able to trim out capacitance variation. I also have a bandgap VREF available as well as a low tempco IREF.
I have done a relaxation oscillator that went about 10MHz using a relaxation oscillator before, but I'm having doubts about the same architecture working 10x faster.
Horror Vacui wrote on Apr 3rd, 2020, 5:30pm:It is a tough question. I assume of course, that you are looking for a fully integrated architecture without off-chip crystal or resonator.
I see the problem in capacitance variations. All oscillators I am aware of utilize capacitance to determine the oscillation frequency, and on-chip - but even off-chip - capacitors tend to be inaccurate in absolute terms. In order to calibrate it, one need either capacitance or timing reference.
The standard low frequency oscillator topologies are current starved ring and relaxational oscillator, where a cap is charged to a threshold and then discharged.
If you find any good architecture, please share it here.