Hello, I've been doing some experiments in Spice with current sources trying to develop a circuit that can generate triangle waves such that it is possible to change the steepness of the rising and falling edges of the wave while maintaining a stable amplitude with respect to the "duty cycle" of the wave. (if you know a circuit that can manage that from 0hz to ~100Mhz then please tell, it would save me some thinking).
The result of that thinking was a circuit that could change the charge and discharge speed of a capacitor by changing two control voltages, after doing some math I found out that if I wanted to have a stable amplitude the charge(V꜀) and discharge speeds(V₋꜀) of the cap need to be a function of the duty cycle (D) such that
V꜀ = 1/D
V₋꜀ = 1/1-D
Therefore the problem becomes how do I convert a linear control voltage to a output voltage that is inversely proportional to the control voltage. I am aware that this is not possible with 100% accuracy but I would like to create such a curve down to about 5-10% duty cycle which corresponds to about 10-20x "amplification" from the lowest value.
The main problem I've faced here is that all the amplification techniques I can think of are proportional and I haven't found a way to flip that around.
I'll also mention that this is just a thought experiment I found interesting, the control voltages here don't have any real switching speed requirements and therefore can easily be created with a DAC fed from a MCU that has these curves in code, however I thought it would be neat to try to do it in the analog realm. Thanks in advance.