How to test this crystal oscillator?

I have a crystal oscillator part no :fx135a-327 . i was looking into its datasheet for the test circuit but it does not have.So please help me out with some simple test circuits .
I want to calculate frequency stability, Rise time Fall Time,Startup time etc.


What is the Input to be given >

One solution is circuit given

You can calculate the frequency stability, but its meaning less as the rest of the circuit will be less stable then the crystal. Unless you actually build your clock or have a rubidium controlled counter, its difficult even to measure the accuracy. Unless you are just using it as a basis for audio tones
Frank

angy said:

One solution is circuit given

Click to expand...

I played with this same circuit. It works okay. You might need to reduce the 10M resistor until you get oscillations. Avoid reducing the 300k unless you have to. It might expose it to overmuch voltage/ current. I'm pretty sure I did this to a crystal, changing its operating characteristics.

angy said:

I have a crystal oscillator part no :fx135a-327 . i was looking into its datasheet for the test circuit but it does not have.So please help me out with some simple test circuits .
I want to calculate frequency stability, Rise time Fall Time,Startup time etc.


What is the Input to be given >

Click to expand...

Stability is measured over temperature range and compared with spec.
Load and stray capacitance may affect stability if not using COG type caps, then otherwise only affect accuracy at '25'C. Startup time t, is function of 1/3BW, where BW(3dB down)=f0/Q, where high Q like 10k is good and thus slow rise time

BradtheRad said:

I played with this same circuit. It works okay. You might need to reduce the 10M resistor until you get oscillations. Avoid reducing the 300k unless you have to. It might expose it to overmuch voltage/ current. I'm pretty sure I did this to a crystal, changing its operating characteristics.

Click to expand...

What variable capacitor value mentioned in circuit did you set?

Read the datasheet.

FX135A-327 is specified for a load capacitance of 12.5 pF. Means variable capacitor + CMOS inverter input capacitance, in series with 30 pF should be equal to this value for a frequency accuracy in the +/- 20 ppm range. Tune the capacitor for zero frequency error.

I am trying with this circuit to generate oscillation , but with no success ,I am using variable capacitor value of 28pf. Transistor used is BC547. Any suggestions.

Presume the circuit can't work. Bipolar transistor amplifier has much too low input impedance.

It might be possible to redesign the circuit, high series resistance and very low drive level rating of the watch crystal must be however considered. I don't see a purpose in doing it.

FvM said:

Presume the circuit can't work. Bipolar transistor amplifier has much too low input impedance.

It might be possible to redesign the circuit, high series resistance and very low drive level rating of the watch crystal must be however considered. I don't see a purpose in doing it.

Click to expand...

Kindly help me giving some design ideas.
Other circuiit which i tried was


But this to is not working
What change I have done is replaced inveter with SN74LS14. But I am not getting output .Crystal used is FX135A-327 .Any idea why its not working .
Should I change Load capacitance from 22pf to 12.5 pf.Is IC SN74LS14 correct for this testing.

LVC1GU04 sounds good, a Schmitt-trigger gate not at all. LS has also low input impedance and would require redesign, similar to BC547. Why should we use it? LS logic had it's high time in the 60th and 70th, did anybody use it after 80th, except for repair purposes?

The 47k power supply series resistors seem like a bad idea, too.

Again..stability is not tolerance.
tolerance is error at 25'C
stability is VS temp. + aging for all crystals !!

Reduce series R 300k to 10k
The 1uW power limit is actually done by cap shunt current and high input impedance and feedback R, not output impedance.
The series R acts as LPF for overtones and you may be attenuating fundamental.(guess)

300k*22pF= 6.6ns. (guess not)

Consider your CMOS inverter 74HCxx or 74LVCxx has a blown input from ESD.
Measure Vdc of output and input with 10M probe. Now input is attenuated 50% and duty cycle changes on output.
Next change 10M to 1M and repeat probe above. If Vin is not near Vcc/2, is is a dead gate. Vin must Equal Vout avg with 50% duty cycle when operating normal since chip gain is >10x for non buffered and >1000x for (3 stage) buffered and you have a negative feedback linear amp phase shift oscillator.
It won't work on TTL directly (74LSxx) due to IIL input low current, Ensure Vcc decoupling cap near Chip

If all else fails , you have blown your first microslice MEMs tuning fork rated for 1uW max due to invalid 74LS application or ESD. congrats.

FvM said:

LVC1GU04 sounds good, a Schmitt-trigger gate not at all. LS has also low input impedance and would require redesign, similar to BC547. Why should we use it? LS logic had it's high time in the 60th and 70th, did anybody use it after 80th, except for repair purposes?

The 47k power supply series resistors seem like a bad idea, too.

Click to expand...

What if i replace IC with 74HC04. Will circuit work?

'LVC04's & 'HC04's are used all the time on correct Vcc.
Did you follow or read my post?