VERY HIGH RDS DEMODULATION QUALITY

WITH IMPROVED DIGITAL SIGNAL PROC-

ESSING

HIGH PERFORMANCE, 57KHz BANDPASS

FILTER (8th ORDER)

FILTER ADJUSTMENT FREE AND WITHOUT

EXTERNAL COMPONENTS

PURELY DIGITAL RDS DEMODULATION

WITHOUT EXTERNAL COMPONENTS

ARI (SK INDICATION) AND RDS SIGNAL

QUALITY OUTPUT

4.332MHz CRYSTAL OSCILLATOR

(8.664 and 17.328MHz OPTIONAL)

LOW NOISE CMOS TECHNOLOGY

LOW RADIATION

DESCRIPTION

The TDA7479 recovers the additional inaudible

RDS information which is transmitted by FM radio

broadcasting stations and operates in accord-

ance with the EBU (European Broadcasting Un-

ion) specifications.

The device is made up of two sections: a cas-

caded antialiasing + switched capacitors band-

pass filter for precise RDS band selection and a

demodulating section that performs the extraction

od RDS data stream (RDDA) and clock (RDCL),

to be furher processed by a suitable RDS de-

coder.

Outputs for RDS signal quality and ARI indication

are also present.

February 1998

2nd ORDER

ANTIALIASING

FILTER

8th ORDER

SC-BANDPASS

FILTER

MPX

4

270pF

-

+

8

FILOUT

12

3

VREF

100nF

10

µF

OSCILLATOR &

DIVIDER

57KHz PLL

FAST ARI

INDICATOR

POLARITY

BIPHASE DEC.

INTEGRAL

BIPHASE DEC.

1187.5Hz

PLL

MUX

0

1

DIFF. DECODER

TEST LOGIC

QUAL DET.

6

GND

11

EXTRES

14

13

5

9

16

7

1

D97AU751A

TM

10

RDDA

2

QUAL

ARI

RDCL

FSEL

OSEL

OSCOUT

OSCIN

4.332MHz

C2 47pF

C1 27pF

15

T57

BLOCK DIAGRAM AND TEST CIRCUIT

TDA7479

SINGLE CHIP RDS DEMODULATOR + FILTER

DIP16

SO16

ORDERING NUMBERS:

TDA7479

TDA7479D

1/7