MB15F04 Datasheet, PDF (13/23 Pages) Fujitsu Component Limited. – Dual Serial Input PLL Frequency Synthesizer

MB15F04
s ANALOG SWITCH (BSCTX Pin)
The analog switch is set on or off by the BSCTX input. When the switch is on, the output of the charge pump (DoTX)
is output from the BSTX pin. (The pin goes to high impedance when the switch is off.)
Analog switch
ON
OFF
BSCTX
H
L
As in the example shown in the figure below, placing the analog switch midway through the LPF (LPF1 + LPF2)
allows the LPF time constant to be reduced during PLL channel switching so as to speed up the lock up time.
CHP
DoTX
LPF1
LPF2
VCO
Analog
swtch
BSTX
BSCTX
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