SILAN SC6579, SC6579S Datasheet
Silan
Semiconductors
RADIO DATA SYSTEM (RDS)
DEMODULATOR
DESCRIPTION
The integrated CMOS circuit SC6579 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).
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 bi-phase data rate
• Bi-phase symbol decoder with integrate and dump functions
• Differential decoder
• Signal quality detector
• Subcarrier output.
SC6579
DIP-16
SOP-16
ORDERING INFORMATION
Device Package
SC6579 DIP16-300-2.54
SC6579S SOP-16-225-1.27
PIN CONFIGURATION
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
QUAL
RDDA
V
MUX
DDA
V
V
SSA
CIN
SCOUT
1
2
3
ref
4
5
6
7
8
SC6579
16
15
14
13
12
11
10
9
RDCL
T57
OSCO
OSCI
DDD
V
V
SSD
TEST
MODE
1
Rev: 1.0 2001.12.30
Silan
Semiconductors
BLOCK DIAGRAM
SC6579
82pF
+5V
0.1F
DDD
V
121413
quality bit
generator
differential
decoder
SSD
MPX
signal
2.2
SCOUT
560pF
+5V V
0.1F
F
MUX
330pF
CIN
DDA
Vref
4
8
7
5
3
anti-
aliasing
filter
clocked
comparator
reference
voltage
6
47pF
4.332/8.664MHz
57kHz
bandpass
(8th order)
costas loop
variable and
fixed divider
P1
V
clock
regeneration
and sync
V
SSA
reconstruction
filter
SC6579
oscillator and
bi-phase
symbol
decoder
test logic and output
selector switch
91011
MODE TEST V
2.2K
OSCI OSCO
divider
Via pin MODE two different crystal frequencies can be used.
MODE CRYSTAL CLOCK
LOW 4.332 MHz
HIGH 8.664 MHz
ABSOLUTE MAXIMUM RATINGS
Characteristic Symbol Value Unit
Analog Supply Voltage (pin 5) V
Digital Supply Voltage (pin 12) V
Voltage on All Pins; Grounds Excluded Vn -0.5 ~ V
Storage Temperature T
Operating Ambient Temperature T
Electrostatic Handling for All Pins Except
Pins 9 and 10
Notes1. Equivalent to discharging a 200 pF capacitor via a 0 Ω series resistor.
2. Equivalent to discharging a 100 pF capacitor via a 1.5 kΩ series resistor.
(Ta=25°C)
0~ 6 V
DDA
0~ 6 V
DDD
+ 0.5 V
DD
-40 ~+150 °C
stg
-40 ~+85 °C
amb
V
ESD
±300 note 1 V
+1500 ~-3000 note 2 V
QUAL
1
RDDA
2
RDCL
16
15 T57
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
2
Rev: 1.0 2001.12.30
Silan
Semiconductors
ELECTRICAL CHARACTERISTICS
(V
=V
DDD
=5 V; T
DDA
Parameter Symbol Test condition Min. Typ. Max. Unit
Analog Supply Voltage (pin 5) V
Digital Supply Voltage (pin 12) V
Total Supply Current I
Reference Voltage (pin 3) V
MPX input (signal before the capacitor on pin 4)
RDS Amplitude (RMS value) V
Maximum Input Signal Capability
(peak-to-peak value)
Input Resistance R4-6 f = 0 to 100kHz 40 -- -Signal Gain G8-4 f = 57 kHz 17 20 23 dB
57 kHz band-pass filter
Center Frequency fc T
-3 dB Bandwidth B 2.5 3.0 3.5 kHz
Stop Band Gain G
Output Resistance (pin 8) R
Comparator input (pin 7)
Minimum Input Level (RMS value) V
Input Resistance Ri 70 110 150
Oscillator input (pin 13)
HIGH-level Input Voltage VIH V
LOW-level Input Voltage VIL V
Input Current II V
=25°C and measurements taken in Fig.1; unless otherwise specified.)
amb
3.6 5.0 5.5 V
DDA
3.6 5.0 5.5 V
DDD
tot
ref
i MPX (rms)
V
i MPX (p-p)
o(8)
i(rms)
I
V
+I12 6 mA
5
= 5 V 2.5 V
DDA
∆f ±1.2 kHz RDS;
∆f ±3.5 kHz ARI; see Fig.5
f = 5±2 kHz 200 -- -- mV
f < 50 kHz 1.4 -- -- V
f < 15 kHz 2.8 -- -- V
f > 70 kHz 3.5 -- -- V
= -40 to +85 °C 56.5 57.0 57.5 kHz
amb
∆f =±7 kHz
f < 45 kHz 40 -- -- dB
f < 20 kHz 50 -- -- dB
f > 70 kHz 40 -- -- dB
f = 57 kHz -- 26 --
f = 57 kHz -- 1 10 mV
= 5.0 V 4.0 -- -- V
DDD
= 5.0 V -- -- 1.0 V
DDD
= 5.5 V -- -- ±
DDD
31 -- -- dB
SC6579
1 -- -- mV
kΩ
Ω
kΩ
µA
To be continued
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
3
Rev: 1.0 2001.12.30
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