# high frequency sawtooth oscillator

Discussion in 'General Electronics Chat' started by DominusDRR, May 25, 2009.

1. ### DominusDRR Thread Starter Member

May 25, 2009
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Is there a diagram of a high frequency sawtooth oscillator? 100MHz​

I'm going to use HFA1109 Amp Op.​

Fabián​

2. ### Wendy Moderator

Mar 24, 2008
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At that frequency it is going to be hard. You know how harmonics relate to waveforms, right?

3. ### KL7AJ AAC Fanatic!

Nov 4, 2008
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Indeed....that's even pushing the recovery time of a xenon relaxation oscillator!

eric

4. ### beenthere Retired Moderator

Apr 20, 2004
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Perhaps you could say why a sawtooth waveform is necessary?

5. ### DominusDRR Thread Starter Member

May 25, 2009
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Yes. Definitely, I know about harmonics. I am not an expert in high frequency electronics, but I hope I will generate voltage signal​

6. ### DominusDRR Thread Starter Member

May 25, 2009
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I need to generate this signal to compare with other lower frequency signal. Something like a PWM or SPWM

Fabian​

Apr 5, 2008
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Hello,

Why do you need 100 Mhz?
What is the maximum frequency you use for the other comparing part?

Greetings,
Bertus

8. ### DominusDRR Thread Starter Member

May 25, 2009
26
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The other is 1MHz @ 10 MHz

9. ### Wendy Moderator

Mar 24, 2008
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Thing is, you're frequency response is going to be way past 500Mhz. That is the 5X harmonic. For a decent waveform you'll need really high frequency response.

At that frequency making a square wave is even harder, for the same exact reason. Square waves are usually used to generate triangle waves, but I think we can say this won't be practical at this frequency. The logic family ECL operates in this region, and gets around it by deliberately rounding the edges. A continuous logic chain in ECL resembles a sine wave more than a square wave.

10. ### DominusDRR Thread Starter Member

May 25, 2009
26
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And.. a DDS. Is it best?

Apr 5, 2008
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12. ### millwood Guest

that's an interesting design.

1) the mcu takes usb signal and sends out i2c. I would love to see their source code, for that.

2) the si570 is quite amazing. programmable oscillator. conceiveably, you can just take a mcu to control that with up/down buttons but controlling it with a pc through usb must be fun.

13. ### millwood Guest

the way they do tempco compensation is very smart.

it looks like a well thought-out and well designed package.

Nov 28, 2008
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