Bias resistor
inaki
Posts: 262
I am going to use a 6.5Mhz resonator with a SX28AC.
Do I need to place a bias resistor ? If so, which resistance would be suitable ?
The reason I have chosen the 6.5Mhz is that I have a lot of them. They are pretty old parts.
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Do I need to place a bias resistor ? If so, which resistance would be suitable ?
The reason I have chosen the 6.5Mhz is that I have a lot of them. They are pretty old parts.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Comments
Recomended oscillator components are shown on page 159 of the "SX-key/Blitz! Development System Manual, Version 1.1".
For 6.5MHz these are Rp=1Mohm, C1=20pF, C2=47pF.
Old crystals may have higher Equivalent Series Resistance, ESR, or non-standard static capacitance C0; in this case you may need to experiment with these component values in order to obtain reliable oscillation. If the crystal clock fails to oscillate try varying Rp in the range 1Mohm to 3.3kohm or try different values for the osc device directive (page43).
Best regards
electronic