Looking for state-of-the-art crystal circuit for approx 10MHz
时间:04-06
整理:3721RD
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Hello,
I've seen various xtal circuits, and read some dated books, however, does anyone have a circuit diagram of a good contemporary state-of-the-art circuit for a 10MHz oscillator with some component values?
With very low phase noise close-in (-110 or lower at 10Hz), of the order of some OCXOs costing £250 or more
(I don't need an OCXO, but I do need very low phase noise).
Also, I got some xtals made from ICM a while back (unrelated to above, an overtone frequency) and I was told there was
no particular recommended circuit for them, as long as the circuit presents a 32pF load to the xtal.
The datasheet also didn't say much (it is pasted below). Do xtal manufacturers need to be given more information if
I want an xtal and I'm concerned about low phase noise?
Any easily-obtainable off-the-shelf decent 10MHz xtal anyone can recommend?
Thanks!
1. Frequency: 111-139.99 Mhz
2. Holder Type:HC-35/U
3. Calibration
Tolerance:±25 PPM
At 26oC
4. Stability:±30 PPM From -10 TO +60oC
5. Circuit Condition:32 PF
7. Shunt Capacitance: 6PF
MAX.
8. Series Resistance: 65
OHMS MAX
9. Mode of
Oscillation:5TH
overtone
14. Marking: STANDARD
I've seen various xtal circuits, and read some dated books, however, does anyone have a circuit diagram of a good contemporary state-of-the-art circuit for a 10MHz oscillator with some component values?
With very low phase noise close-in (-110 or lower at 10Hz), of the order of some OCXOs costing £250 or more
(I don't need an OCXO, but I do need very low phase noise).
Also, I got some xtals made from ICM a while back (unrelated to above, an overtone frequency) and I was told there was
no particular recommended circuit for them, as long as the circuit presents a 32pF load to the xtal.
The datasheet also didn't say much (it is pasted below). Do xtal manufacturers need to be given more information if
I want an xtal and I'm concerned about low phase noise?
Any easily-obtainable off-the-shelf decent 10MHz xtal anyone can recommend?
Thanks!
1. Frequency: 111-139.99 Mhz
2. Holder Type:HC-35/U
3. Calibration
Tolerance:±25 PPM
At 26oC
4. Stability:±30 PPM From -10 TO +60oC
5. Circuit Condition:32 PF
7. Shunt Capacitance: 6PF
MAX.
8. Series Resistance: 65
OHMS MAX
9. Mode of
Oscillation:5TH
overtone
14. Marking: STANDARD
For low phase noise you can use a Wenzel type oscillator, as this one:
http://www.wenzel.com/pdffiles1/pdfs/xtalosc.pdf
Or Driscoll type:
http://www.ko4bb.com/~bruce/XTALOSC.html
Thanks for the links!
