Harman Kardon AVR 3550 - Page 39

RDS demodulator (SAA6579TV1) : IC71
BLOCK DIAGRAM
handbook, full pagewidth
SAA6579
0.1 µF
ANTI-
ALIASING
FILTER
57 kHz
BANDPASS
(8th ORDER)
RECONSTRUCTION
FILTER
OSCILLATOR
AND
DIVIDER
CLOCKED
COMPARATOR
COSTAS LOOP
VARIABLE AND
FIXED DIVIDER
CLOCK
REGENERATION
AND SYNC
BIPHASE
SYMBOL
DECODER
DIFFERENTIAL
DECODER
TEST LOGIC AND OUTPUT
SELECTOR SWITCH
REFERENCE
VOLTAGE
2.2 µF
4
7
8
5
3
6
V
DDA
V
ref
V
P1
13
14
QUAL
RDDA
RDCL
T57
QUALITY BIT
GENERATOR
1
2
15
16
11
12
2.2 k
Ω
82 pF
47 pF
4.332/8.664 MHz
MPX
signal
330 pF
9
10
MODE TEST
560 pF
MEH162
V
SSD
V
DDD
+5 V
+5 V
OSCOOSCI
MUX
SCOUT
CIN
0.1 µF
V
SSA
Fig.1 Block diagram and application circuit.
Via pin MODE two different crystal frequencies can be used.
MODE CRYSTAL CLOCK
LOW 4.332 MHz
HIGH 8.664 MHz