2.56 MHz
φ
TO
AM/FM
OSCILLATORS
–
+
f
R
in
MC12019
20 PRESCALER
FM
OSC
MC145155–2
φ
V
÷
1/2 MC1458*
AM
OSC
DATA
CLK
ENB
CMOS
MPU/MCU
KEYBOARD
TO DISPLAY
* The φ and φ outputs are fed to an external combiner/loop filter. See the Phase–Locked Loop — Low–Pass Filter Design page
R
V
foradditionalinformation.Theφ andφ outputsswingrail–to–rail. Therefore, theusershouldbecarefulnottoexceedthecommon
R
V
mode input range of the op amp used in the combiner/loop filter.
Figure 2. AM/FM Radio Synthesizer
MC145155–2 Data Sheet Continued on Page 23
MC145151–2 through MC145158–2
12
MOTOROLA