TDA7326 Datasheet, PDF (7/16 Pages) STMicroelectronics – AM-FM RADIO FREQUENCY SYNTHESIZER

Figure 3: AM direct mode operation for SW, MW and LW
OSC IN
PREDIVIDER
R
fref
PD
fsyn
TDA7326
AM IN
FM IN
MSB
REGISTER
PC7 .. PC0
REGISTER
SC5 .. SC0
COUNTER : C
D94AU102
3.4 REFERENCE FREQUENCY GENERATOR
TABLE 3.4
The crystal oscillator clock is divided by the
reference frequency divider to provide the ref-
AM/FM
f_REF
erence frequency to the phase comparator.
0
0
Reference frequency divider range is select-
0
1
able by the programming bit ’fREF’.
Available reference frequency are shown in
1
0
following table.
1
1
Figure 4: Phase comparator
f_REF (kHz)
12.5
25
1
2.5
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