Document
INTEGRATED CIRCUITS
DATA SHEET
SAA6579 Radio Data System (RDS) demodulator
Product specification Supersedes data of January 1994 File under Integrated Circuits, IC01 1997 Feb 24
Philips Semiconductors
Product specification
Radio Data System (RDS) demodulator
FEATURES • Anti-aliasing filter (2nd order) • Integrated 57 kHz band-pass filter (8th order) • Reconstruction filter (2nd order) • Clocked comparator with automatic offset compensation • 57 kHz carrier regeneration • Synchronous demodulator for 57 kHz modulated RDS signals • Selectable 4.332/8.664 MHz crystal oscillator with variable dividers • Clock regeneration with lock on biphase data rate • Biphase symbol decoder with integrate and dump functions • Differential decoder • Signal quality detector • Subcarrier output. QUICK REFERENCE DATA SYMBOL VDDA VDDD Itot Vi(rms) VOH VOL Tamb PARAMETER analog supply voltage (pin 5) digital supply voltage (pin 12) total supply current RDS input amplitude (RMS value; pin 4) HIGH level output voltage for signals RDDA, RDCL, QUAL and T57 LOW level output voltage for signals RDDA, RDCL, QUAL and T57 operating ambient temperature MIN. 3.6 3.6 − 1 4.4 − −40 TYP. 5.0 5.0 6 − − − − GENERAL DESCRIPTION
SAA6579
The integrated CMOS circuit SAA6579 is an RDS demodulator. It recovers the additional inaudible RDS information which is transmitted by FM radio broadcasting. The data signal RDDA and the clock signal RDCL are provided as outputs for further processing by a suitable decoder (microcomputer). The operational functions of the device are in accordance with the “CENELEC EN 50067”.
MAX. 5.5 5.5 − − − 0.4 +85
UNIT V V mA mV V V °C
ORDERING INFORMATION TYPE NUMBER SAA6579 SAA6579T PACKAGE NAME DIP16 SO16 DESCRIPTION plastic dual in-line package; 16 leads (300 mil); long body plastic small outline package; 16 leads; body width 7.5 mm VERSION SOT38-1 SOT162-1
1997 Feb 24
2
Philips Semiconductors
Product specification
Radio Data System (RDS) demodulator
BLOCK DIAGRAM
SAA6579
handbook, full pagewidth
47 pF 4.332/8.664 MHz
82 pF +5 V 2.2 k Ω OSCI 13 OSCO 14
0.1 µF
VDDD 12
MPX signal
MUX 4 330 pF SCOUT 8 560 pF CIN 7
ANTIALIASING FILTER
57 kHz BANDPASS (8th ORDER)
RECONSTRUCTION FILTER
OSCILLATOR AND DIVIDER
QUALITY BIT GENERATOR
1 QUAL
CLOCKED COMPARATOR
COSTAS LOOP VARIABLE AND FIXED DIVIDER
BIPHASE SYMBOL DECODER
DIFFERENTIAL 2 DECODER 16
RDDA
+5 V
VDDA 5
0.1 µF
SAA6579
VP1 CLOCK REGENERATION AND SYNC
RDCL
Vref 3
REFERENCE VOLTAGE
TEST LOGIC AND OUTPUT SELECTOR SWITCH
15
T57
2.2 µF
6 VSSA
9 MODE
10 TEST
11 VSSD
MEH162
Via pin MODE two different crystal frequencies can be used.
MODE LOW HIGH
CRYSTAL CLOCK 4.332 MHz 8.664 MHz Fig.1 Block diagram and application circuit.
1997 Feb 24
3
Philips Semiconductors
Product specification
Radio Data System (RDS) demodulator
PINNING SYMBOL QUAL RDDA Vref MUX VDDA VSSA CIN SCOUT MODE TEST VSSD VDDD OSCI OSCO T57 RDCL PIN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 quality indication ou.