For customers designing Freescale Semiconductor IC
MC132xx Series ZigBee/IEEE802.15.4 applications
The following provides a basic explanation of design considerations for the external oscillation circuit using quartz crystal for 'Low Power RF' technology including ZigBee,IEEE802.15.4 wireless applications. "Please refer to Freescale Semiconductor ZigBee/IEEE802.15.4 solution below."
Please refer to Freescale Semiconductor official site for additional information.
In realizing low power consumption RF designs, the following factors should be taken into consideration.
- Oscillation start-up time
- Frequency tuning
- Lower BER(Bit Error Rate) over operating temperature
|No.||Oscillation Circuit Factor||2.4 GHz|
|< AT crystal unit spec.>|
|1||Quick oscillation start-up time
*High oscillation allowance
*High drive level
|2||Easy frequency control
*inner frequency tuning capacitor
|*proper frequency sensitivity
*low parameters' variation
|*High frequency stability|
|MHz Crystal equivalent circuit|
| Rapid Oscillation start-up time
--> Lower ESR (R1) , Higher C1
--> Higher drive level
--> Lower parameters variation(C0,C1,L1,ESR)
|Suitable Frequency Tuning
--> Proper Sensitivity (CL,C0)
|Higher Frequency Stability
--> Stable fSTA
Clock solution recommendations for Freescale MC132xx Series
|MC1322x (SoC)||MC1323x (SoC)|
|2400 to 2483.5 MHz|
16 MHz 9 pF
24 MHz 9 pF
Notes:Above recommendations are based on actual evaluation results and intended to support
users in picking the right components. And the results are only according to the sample
set that received from our customers, so it is not including the dispersion trend of IC
and the external parts.
As the actual board layout and choice of external components influences the best suitable crystal load capacitance, We do not assume any responsibility and grant warranty for above recommendations. Users design must be verified and decided by own and individual evaluation.
*ZigBee is a registered trademark of Koninklijke Philips Electronics N.V.