Hi all, I have this crystal oscillator
which works fine.
The circuit is taken from the TX-2B datasheet at page 9 first circuit.
The oscillator works fine, but I am interested in calculate his total impedance.
If I am not wrong, in a first moment the crystal is pushed by the current coming from R1 and then is pulled back by the L1C2 network.
As I can see from the crystal's datasheet used, between 27 & 30Mhz in 3rd overtone the ESR of the crystal is about 150 Ohm.
If the 27MHz frequency is applied to L1 & C1, I obtain the following impedance,
XL = 2π · 27MHz · 2,2uH = 373,22 Ohm
XC = 1 / [ 2π · 27MHz · 80pF ] = 73,68 Ohm
and adding the Crystal ESR, I obtain the following resistive network
but I am not sure it is correct.. Maybe (or off course) the situation is more complex and, as I expect, I am out of way.
Can you help me to determine the total circuit impedance please?
The real circuit, with power supply of approximately 9.19V consumes about 29.2 mA.
Regards,
Simon
which works fine.
The circuit is taken from the TX-2B datasheet at page 9 first circuit.
The oscillator works fine, but I am interested in calculate his total impedance.
If I am not wrong, in a first moment the crystal is pushed by the current coming from R1 and then is pulled back by the L1C2 network.
As I can see from the crystal's datasheet used, between 27 & 30Mhz in 3rd overtone the ESR of the crystal is about 150 Ohm.
If the 27MHz frequency is applied to L1 & C1, I obtain the following impedance,
XL = 2π · 27MHz · 2,2uH = 373,22 Ohm
XC = 1 / [ 2π · 27MHz · 80pF ] = 73,68 Ohm
and adding the Crystal ESR, I obtain the following resistive network
but I am not sure it is correct.. Maybe (or off course) the situation is more complex and, as I expect, I am out of way.
Can you help me to determine the total circuit impedance please?
The real circuit, with power supply of approximately 9.19V consumes about 29.2 mA.
Regards,
Simon
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