4049 NOT gates design of oscillator

[Favor]

How to design an oscillator with 3three 4049 NOT gates a resistor and a capacitor

 

[Pommie]

You'd be better using a chip with a schmitt trigger input such as the 7414 and google schmitt oscillator.

Mike.

 

[ronsimpson]

 

[audioguru]

The output source and sink currents in a CD4049 are not symmetrical like on a CD4069. The datasheet for the CD4049 even recommends using the CD4069 when the high sink current from the CD4049 is not needed.

The input clamps on a CD4049 are also not symmetrical like they are on a CD4069.

I have made hundreds of oscillators with two CD4069 inverters or inverting Cmos Gates and many oscillators with 74C14 Cmos Schmitt Trigger input inverters.

 

[Favor]

Thanks for the answers, you have the circuit I wanted but how to calculate the differs parameters of the circuit and how to sketch the votages of the not gate and the out voltage is my main worry.


Please, how do I calculate my desired resistances capacitance, period and frequency of oscillation?

 

[audioguru]

Please, how do I calculate my desired resistances capacitance, period and frequency of oscillation?

In post #3 you were given the schematic of the old oscillator made with three Cmos inverters and a link to the oscillator's applications note that tells you all about it. It does not use the asymmetrical CD4049, instead it uses the 74C04 (same as a CD4069) that I noted.

 

[AnalogKid]

you have the circuit I wanted but how to calculate the differs parameters of the circuit and how to sketch the votages of the not gate and the out voltage is my main worry.

Please, how do I calculate my desired resistances capacitance, period and frequency of oscillation?

This sounds like homework.

First, you still have not said which circuit you are using. The calculations are different for each one.

Second, post your work so far with your calculations or ideas on how the circuit works, and we will advise.

ak

 

[dr pepper]

Google found this, it has an online calc within;

Art's Theremin Page: CMOS Oscillator Frequency Calculator

Take care with the 4049, there is a 4049 ub which is an unbuffered version, some circuits require the unbuffered version to work.