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PL560-08_12 Datasheet, PDF (6/12 Pages) Micrel Semiconductor – Analog Frequency Multiplier | |||
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(Preliminary) Analog Frequency Multiplier
PL560/565-08 VCXO Family
AFM QFN PACKAGE APPLICATION CIRCUIT
RECOMMENDED PCB LAYOUT
ï· Avoid ground planes underneath the crystal
and inductor traces to limit parasitic
capacitance.
ï· Add bypass capacitor close to VDDBUF pin.
ï· Avoid bypass capacitors near VDDOSC pins to
lower cross-talk of unwanted frequencies.
ï· L1X(a,b) can be used to increase the VCXO
pulling range. Using a ferrite core inductor
limits the oscillation amplitude which can have
a positive effect on phase noise.
ï· L2X and L4X tune the frequency multiplier tank
circuits. They need to be wire wound inductors
with high Q-factor, preferably >20.
ï· The large center pad is the âthermal reliefâ pad
and can be connected to ground.
Micrel Inc. ⢠2180 Fortune Drive ⢠San Jose, CA 95131 ⢠USA ⢠tel +1(408) 944 -0800 ⢠fax +1(408) 474-1000 ⢠www.micrel.com Rev 6/22/11 Page 6
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