Rev. 4757A–AUDR–10/03

Features

–AM

≥ 1 kHz

–FM

≥ 2 kHz

Description

The U4289BM is an integrated circuit in BICMOS technology for frequency synthesiz-

ers. It performs all the functions of a PLL radio tuning system and is controlled by a

2-wire bus. The device is designed for all frequency synthesizer applications in radio

receivers, as well as for RDS (Radio Data System) applications.

Figure 1. Block Diagram

R-divider

N-divider

interface

Oscillator

Phase

Current

sources

AM/FM

14

15

2

3

4

6

8

OSCOUT

OSCIN

SCL

AS

FMOSC

AMOSC

SDA

5

7

1

16

SWO1

11

12

13

9

10

PDAM

PDAMO

VA

PDFMO

PDFM

GND2

GND1

DD

V

switch

Switching

output

detector

AM/FM PLL

with 1 Switch

U4289BM