ST TDA7479 User Manual

Single chip RDS demodulator + filter

Features

■ Very high RDS demodulation quality with

improved digital signal processing

■ High performance, 57 kHz bandpass filter

th

(8

order)

■ FIlter adjustment free and without external

components

■ Purely digitaL RDS Demodulation without

external components

■ ARI (SK indication) and RDS signal quality

output

■ 4.332 MHz crystal oscillator

(8.664 and 17.328 MHz 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 accordance
with the EBU (European Broadcasting Union)
specifications.

Table 1. Device summary

TDA7479

SO16

TSSOP16

The device is made up of two sections: a
cascaded antialiasing + switched capacitors 8
bandpass filter for precise RDS band selection
and a demodulating section that performs the
extraction od RDS data stream (RDDA) and clock
(RDCL), to be further processed by a suitable
RDS decoder.

Outputs for RDS signal quality and ARI indication
are also present.

th

Order code Package Packing

E-TDA7479D

E-TDA7479AD

1. Device in ECOPACK® package (see Section 5: Package information on page 9).

November 2008 Rev 7 1/12

(1)

(1)

SO16 Tube

TSSOP16 Tube

www.st.com

12

Contents TDA7479

Contents

1 Block diagram and pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.1 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.2 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 Electrical specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.1 Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.2 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.3 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3 Output timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

4 Oscillator controls (FSEL, OSEL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

5 Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

6 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2/12

TDA7479 Block diagram and pin description

1 Block diagram and pin description

1.1 Block diagram

Figure 1. Block diagram

4.332MHz C2 47pFC1 27pF

MPX

V

S

100nF

10μF

270pF

FILOUT

4

8

12

3VREF

GND

2nd ORDER

ANTIALIASING

FILTER

8th ORDER

SC-BANDPASS

FILTER

-

+

6

1.2 Pin description

T57

15

57KHz PLL

FAST ARI

INDICATOR

POLARITY

BIPHASE DEC.

INTEGRAL

BIPHASE DEC.

OSCILLATOR &

DIVIDER

OSCOUTOSCIN

1413

5

OSEL

9

FSEL

16

1187.5Hz
PLL

QUAL DET.

0

MUX

1

EXTRES

DIFF. DECODER

TEST LOGIC

11

D97AU751A

RDCL

7

ARI

1

QUAL

2

RDDA

10

TM

Figure 2. Pin connection (top view)

QUAL

RDDA

VREF

MPX

OSEL

GND

ARI

FILOUT 8 FSEL9

1

2

3

4

5

6

7TM

D97AU752

15

14

13

12

11

10

RDCL16

T57

OSCOUT

OSCIN

V

S

EXTRES

3/12

Block diagram and pin description TDA7479

Table 2. Pin description

No pin Name Description

1 QUAL Output for signal quality indication (High = good)

2 RDDA RDS data output

3 VREF Reference voltage

4 MPX RDS input signal

Oscillator selector pin:

5 OSEL

6 GND Ground

7ARI

8 FILOUT Filter output

9 FSEL

10 TM

– open, closed to V

= quartz oscillator

S

– closed to GND = external driven

Output for ARI indication:
– high when RDS+ARI are present
– high when only ARI is present
– low when only RDS is present
– undefined when nos signal is present

Frequency selector pin:
– 100 kHz to VS = 17.328 MHz
– open = 4.332MHz
– closed to VS = 8.664 MHz

Test mode pin:
– open = normal operation
– closed to VS = test mode

Reset pin:

11 EXTRES

– open = run mode
– -closed to VS = reset condition

12 V

S

Supply voltage

13 OSCIN Oscillator input

14 OSCOUT Oscillator output

15 T57 Testing output pin: 57 kHz clock output

16 RDCL RDS clock output 1187.5 Hz

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