Comparator work in sawtooth generator

[Sabrum]

Hi everyone.  I'm building a saw generator with an exponential converter to control the frequency. I need to get as little saw front as possible. But the comparator LM311 gives out a smooth voltage at the beginning, and then quickly resets it. (1-2 in attachments)

On another forum people said to use a PNP transistor and the other input of the comparator. It works in the simulator (in reality, I haven't soldered it). Also they said that i can remove PNP and use the built-in transistor LM311 for switching, but did not say how. Does anyone know how to do that? (3-4 in attchments)

[Benta]

Your circuit looks very complex to me, and I don't see a necessity for the complexity.

For a sawtooth generator, you basically need a constant current source charging C4, this will give you a linear ramp voltage. When this voltage crosses a certain threshold, the LM311 output transistor turns on and discharges C4.
By defining a hysteresis in the LM311 (positive feedback) you'll have a nice sawtooth wave.

Varying the frequency can be done by making the current source adjustable.

In short, you need the LM311, and handful of resistors and caps, an adjustable current source, and a buffer amp for boosting the voltage over C4.

[w2aew]

I did a video a few years ago that showed a sawtooth/triangle waveform generator using constant current sources, a diode switch and a comparator. You could "start" with this, and modify it to meet your requirements:

[Sabrum]

I did a video a few years ago that showed a sawtooth/triangle waveform generator using constant current sources, a diode switch and a comparator. You could "start" with this, and modify it to meet your requirements

I have already made my generator using the 74hc132 logic chip instead of the comparator. Here only one minus - noise from the logic and a small pedestal at the top of the saw. I thought I made a compromise until you showed me your video. I have not seen such schemes on the internet before. Thanks!

Is it possible to get from this scheme a front less than 100ns? Or just connect one side of switch to ground, instead of current source? And the frequency I can adjust by changing the current in one of the current arms?