Pierce Oscillato r Challenge

[ulot]

Hi,
i'm trying to design a pierce oscillator to generate a 3.5MHz clock but the oscillator isn't oscillating
I'm using SN74LS04N, 1MOhm for R1 and 22pf capacitors and the oscillator but it doesn't oscillate.

I'm not sure what the problem is, the NOT gate is powered, and i've tested the inputs to see if they work, and they do, changed the oscillators, but no difference.

 

[MikeMl]

It is really simple; the 1 to 10meg biasing resistor only works for a CMOS inverter

 

[crutschow]

As Mike noted a 74LS device will not work in your circuit. I know it goes against the grain but look at the data sheet input current requirements for device.

 

[ulot]

thanks, i didn't take not of that, i found the HD74HCU04A, i believe this should work i'm i right?

 

[MikeMl]

Should work.

Reference 1.

Reference 2.