Sawtooth generator circuit

[Derekk02]

Hi all,

I'm looking for a circuit to build an sawtooth generator wich operates at about 10kHz.
Who can help me with that?

Derek

 

[mister_rf]

Dedicated IC function generators: ICL8038, XR2206
https://www.elexs.de/sinus1.htm
https://www.intersil.com/content/dam/Intersil/documents/fn28/fn2864.pdf

But for a cheap version, a 555 timer has a pretty good ramp waveform on the timing capacitor. You can use a opamp buffer/amplifier to prevent loading of this signal.
Also read here:

**broken link removed**
**broken link removed**

 

[Syncopator]

You could use a 555 timer in astable mode. Replace the charging R with a constant current source. The voltage across the C will then be a linear sawtooth.

 

[Derekk02]

I tried making a sawtooth with a 555. It works below 2khz. When I go higher the output signal dissapears.



Thank you.
I think this one is a good starting point.

http://www.edn.com/article/521198-Simple_sawtooth_generator_operates_at_high_frequency.php

What are suitable values for R and C to get 10khz?

 

[Syncopator]

I tried making a sawtooth with a 555. It works below 2khz. When I go higher the output signal dissapears.

The 555 works to a much higher frequency than that - consult the data sheet. It may be worth your time playing with a 555, it's a very useful i.c.

I think this one is a good starting point.

**broken link removed**

You noticed this, didn't you? "Charging the RTCT network at constant voltage causes the ramp, so its response is exponential, approximately linear only for the initial part of the exponential rise.

What are suitable values for R and C to get 10khz?

The data sheet gives this information, as do many other web sites, one of which is

 

[betwixt]

The other method is to use a binary counter and DAC. This will give an extremely linear sawtooth with a fast reset and can span full supply voltage but it does involve a slightly more complicated circuit.

Brian.

 

[goldsmith]

Dear Derek
Hi
See below , please , perhaps , it can help you too :
https://www.edaboard.com/blog/1576/
Best Wishes
Goldsmith

 

[jenifer123]

Here is a circuit diagram, which can help you to design a sawtooth generator:

:roll:

 

[Derekk02]

Tomorrow I'm going to build the circuit that Goldsmith posted. I have a last question.
The pspice simulations show that the signal is from 0V to 10V. How can I arrange that the signal is from -10V to +10V?

 

[godfreyl]

I tried making a sawtooth with a 555. It works below 2khz. When I go higher the output signal dissapears.

If you use a smaller capacitor, it will go faster. Try a capacitor 10 times smaller than what you used before.

 

[Derekk02]

What values do you recommend?

 

[godfreyl]

I don't know what circuit you used before, but this should work. It's similar to what Jenifer posted before. The timing capacitor (C1) just needs to be small enough. 10nF should be OK. You can change R1 to set the frequency.

 

[goldsmith]

Dear Derekk02
Hi
If you want to have simultaneous sawtooth wave , it is pretty simple . add a simple potentiometer , and a negative voltage to one of it's heads and the other head to the sawtooth wave and then the out put will be from center head . so if you play with that potentiometer you can achieve simultaneous wave as well .
Best Wishes
Goldsmith