XR2206 Function Generator: tips for cleaner output signals

[@paulperano9236]

If I recall correctly the XR2206 datasheet refers to a min of 10V, max of 26V. I created my own PCB and running it on a 12V battery its quite stable and I managed to get a little over 2MHz. It may go higher. The output is around half at 2MHz compared with, say 20kHz. That's is not exactly a surprise though. I haven't tried using a higher supply yet but I think I'll have a more of a play with it.

[@philipgiacalone5605]

Thanks for that info. Just had a look at the datasheet and you are exactly right about the voltage range. My bad! I I'll have to relabel my device and try it with higher voltages. The datasheet also shows rapidly rising distortion above 500 KHz. I'll give higher voltages and frequencies a try. Thanks again.

[@philipgiacalone5605]

Just re-checking the documentation that came with this function generator kit from China. It says to use a 9-12v input voltage and that the output waveform is unstable above 12v. Testing shows very little difference at voltages above 12v. I went up to 19v.

[@paulperano9236]

@@philipgiacalone5605 I found at about 2MHz my signal was still symmetrical and the Duty Cycle hovering between 50%-53%. No clipping or distortion. I use the wave shaping trim pots to clean that up. This also can including lowering the output - but hey that what you have amplifiers for 🙂

[@pjones5631]

I picked up one these recently. I get no auido tone when running it through a speaker and when it's powered, I get continuity between square and ground, that seems odd to me. Everything on the board looks good, so I'm thinking it's a possible bad chip?

[@t1d100]

If you are trying to run a speaker directly, I don't think it will not work. I believe that you will need an amplifier. This being after you work out any bugs in the circuit, of course.

[@philipgiacalone5605]

I just verified that this device cannot even drive a tiny speaker. As for continuity, I've measured the resistance with the device turned off. There is about 10 kOhms between the ground pin and either the sine or triangle output pin (depending on the pin jumper). The resistance between the output pin and the ground pin is infinite, if the jumper is out. The resistance is infinite between the sine and triangle output pins, as expected.

[@t1d100]

I think you might fry the chip, if you try to run a speaker. Speakers are low ohm devices. I think you need a preamp and an amp. And, you need to match impedances.