1KHz 20mVp-p sine wave oscillator design

[samy555]

I need a 1KHz 20mVp-p sine wave oscillator?

I searched in Google and found many circuits but no one of them worked properly especially when the output is lowered to 20mVp-p. I have an oscilloscope of 50 MHz BW. I need that circuit to be used as a function generator to examine some low frequency preamplifiers. I have built many circuits but they all had a defect So I hope that one of the members may provide me a proven circuit.
Thank you

 

[KlausST]

Hi,

just use one with 1Vpp sine and use a 2500 : 50 Ohms resistive voltage divider.

Klaus

 

[betwixt]

The last ime I needed somethng like that I used a CD4060 to divide a 4.092MHz crystal down to 1KHz the followed it by several RC filters to produce an almost perfect sine wave. Sounds more complicated that an analog signal source but in reality it uses fewer components and gives a precise frequency.

Brian.

 

[KlausST]

Hi,

the question is: where is the problem?
* is it the frequency stability/precision?
* is it the low signal voltage?
* is the expected distortion?

A PC soundcard should give good qualitiy sine.
The percentual distortion should be less with higher output level, as long as it does not clip.

Then a adequate resistive divider should give low level, high quality sine.

Klaus

 

[ydtech]

If using the soundcard is a problem, try to get hold of an ICL8038 or XR2206 chip. Gives square, triangle and sine waves with very few external components. It's at several volts output, just divide down to whatever is needed.

 

[Warpspeed]

It depends what features of this 1Khz sine wave are most important to you.

Does it have to be EXACTLY 1.000000 Khz ?
Is very low distortion important ?
Does the amplitude have to be exactly 20mV ?

Its pretty easy to get one of those three things right.
Two out of three requires a bit more complexity.