e421371 Datasheet, PDF (12/29 Pages) Fuji Electric – Fractional-N PLL Frequency Synthesizer

MB15F83UL
• Phase Comparator Phase Switching Data Setting
FCC = High
FCC = Low
DO
DO
fr > fp
H
L
fr = fp
Z
Z
fr < fp
L
H
Notes : • Z = High-Z
• Depending upon the VCO and LPF polarity, FC bit should be set.
•Charge pump current select Data Setting (CSC)
CSC
Do current
1
± 6.0 mA
0
± 1.5 mA
• Common setting
• LD/fout Output Select Data Setting
LD/fout
LDS
T1
T2
LD output
0


frIF
1
0
0
fout
frRF
1
1
0
output
fpIF
1
0
1
fpRF
1
1
1
• FC bit Setting
When designing a synthesizer, the FC bit setting depends on the VCO and LPF characteristics.
When the LPF and VCO characteristics are similar to (1) ,
set FC bit “H”.
When the VCO characteristics are similar to (2) ,
set FC bit “L”.
High
(1)
VCO output
frequency
LPF output voltage
(2)
Max.
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