U4285BM
AM / FM - PLL
Description
The U4285BM is an integrated circuit in BICMOS
technology for frequency synthesizers. It performs all the
functions of a PLL radio tuning system and is controlled
by an I
2
C bus. The device is designed for all frequency
synthesizer applications in radio receivers, as well as
RDS (
Radio Data System
) applications.
Features
D
Reference oscillator up to 15 MHz
D
Two programmable 16 bit dividers
adjustable from 2 to 65535
D
4 programmable switching outputs
(open drain up to 15 V)
D
Fine tuning steps:
AM
FM
y
1 kHz
y
2 kHz
D
Few external component required due to
integrated loop-push-pull stage for AM/FM
D
High signal/ noise ratio
Ordering Information
Extended Type Number
U4285BM-AFS
U4285BM-AFSG3
Package
SSO20 plastic
SSO20 plastic
Remarks
Taping according to IEC-286-3
Block Diagram
SWO1 SWO2 SWO3 SWO4
5
6
7
8
OSCIN 18
Oscillator
OSCOUT
19
SCL
2
I
2
C bus
interface
Phase
detector
Current
sources
15
16
17
12
13
N-divider
1
VDD
Figure 1.
20
GND1
PDAMO
VA
C
PDFMO
PDFM
R-divider
Switching outputs
14
PDAM
SDA 3
AS
FMOSC
4
9
AMOSC 11
AM/FM
switch
10
GND2
95 10120
TELEFUNKEN Semiconductors
Rev. A3, 14-May-97
1 (10)
TEMIC [ TEMIC SEMICONDUCTORS ]
