CC430/CC1101 RF XTAL 23.745MHz ???

Is it possible to run the RF on the CC430 range at a lower RF reference osscillator speed? I know that Smart studio limits the RF Xtal to between 26MHz and 27MHz but to achieve some legacy frequencies/modulation schemes on a new product we are considering this family of IC's for  we would need to run off a 23.745MHz oscillator. As long as all of the internal registers are set up correctly is using this lower oscillator frequency likely to break anything. Also if the IC will work with this oscillator what will be the maximum frequency achievable in the 400MHz band?

1 Reply

  • The parts are neither designed nor characterized for lower than 26 MHz crystal oscillator frequency.

    The IF-ADC is very sensitive to sampling frequency, partly due to the low over-sampling which puts a lower limit on the frequency, and partly due to internal loop-delay which generates an upper limit. 

    There is a sharp transition from a working ADC to non-functional ADC/ADC with extremely poor SNR. In addition this limit will vary from chip to chip, with supply and temperature. Thus we can not guarantee performance if you go beyond the specified crystal frequency range.

    The maximum frequency in the 400 MHz band is 464 MHz. Please note that CC1100E has higher maximum frequency in the 400 MHz band than CC1101.