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Page 12 of 35

Issue A

Figure 2. AM/FM Radio Synthesizer

TO

AM/FM

OSCILLATORS

TO DISPLAY

ML12019

÷20 PRESCALER

AM

OSC

FM

OSC

fin

KEYBOARD

CMOS

MPU/MCU

ENB

CLK

DATA

1/2 MC1458*

ML145155

2.56 MHz

φV

φR

+

–

* The φR and φV outputs are fed to an external combiner/loop filter. See the Phase–Locked Loop – Low–Pass Filter Design page

for additional information. The φR and φV outputs swing rail–to–rail. Therefore, the user should be careful not to exceed the common

mode input range of the op amp used in the combiner/loop filter.

ML145155

LANSDALE Semiconductor, Inc.

ML145155