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 and sub 1 GHz band wireless applications.
"Please refer to Renesas Electronics ZigBee/IEEE802.15.4 solution below."

Please refer to Renesas Electronics official site for additional information.

In realizing low power consumption RF designs, the following factors should be taken into consideration.

1. Oscillation start-up time
2. Frequency tuning
3. 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   *Boost inverter	*Lower ESR(R1)   *High drive level
2	Easy frequency control   *inner frequency tuning capacitor	*proper frequency sensitivity  *low parameters' variation
3	Lower BER  *temperature compensation	*High frequency stability

 

MHz Crystal equivalent circuit Rapid Oscillation start-up time → Lower ESR (R1) , Higher C1 → Higher drive level Suitable Frequency Tuning → Lower parameters variation(C0,C1,L1,ESR) Suitable Frequency Tuning → Proper Sensitivity ( CL,C0) Higher Frequency Stability → Stable fSTA     Please refer QMEMS Technology

 

Worldwide				UPD78F8058	M16C/6B3,6B4
US	Europe	Japan	Asia
ZigBee IEEE802.15.4				2400 to 2483.5 MHz
Recommendable Clock Devices				TSX-3225    32 MHz  8 pF (X1E000021049300) FA-20H      32 MHz  8 pF	FA-20H     16 MHz  12 pF (Q24FA20H0023200) TSX-3225   16 MHz  12 pF

Notes:  Above recommendations are based on actual evaluation results and intended to support users in picking the right components. As the actual board layout and choice of external components influences the best suitable crystal load capacitance, we does not assume any responsibility and grant warranty for above recommendations. Users design must be verified and decided by own and individual evaluation.
Please refer to Renesas Electronics 78K0/M16C manual for designing.

 

*ZigBee is a registered trademark of Koninklijke Philips Electronics N.V.