2001 May 07
5
Philips Semiconductors
Product specification
RDS/RBDS demodulator
SAA6581T
Table 1
Control pin SYNC
S
IGNAL QUALITY DETECTION
Output QUAL indicates the safety of the regenerated RDS
data (HIGH = ‘good’ data; LOW = ‘unsafe’ data).
Oscillator and system clock generator
For good performance of the bandpass and demodulator
stages, the demodulator requires a crystal oscillator with a
frequency of 4.332 or 8.664 MHz. The demodulator can
operate with either frequency (see Table 2), so that a radio
set with a microcontroller can run, in this case, with one
crystal only. The demodulator oscillator can drive the
microcontroller, or vice versa.
Table 2
Control pins TCON and MODE
The clock generator generates the internal 4.332 MHz
system clock and timing signal derivatives.
Power supply and internal reset
The demodulator has separate power supply inputs for the
digital and analog parts of the device. For the analog
functions an additional reference voltage (
1
2
V
DDA
) is
internally generated and available via the output pin V
ref
.
The demodulator requires a defined reset condition. The
demodulator generates automatically a reset signal after
the power supply V
DDA
is switched on, or at a voltage-drop.
SYNC
ARI CLAMPING
LOW
HIGH
internal ARI clamping disabled
ARI clamping allowed to be logged
TCON
MODE
OSCILLATOR FREQUENCY
HIGH
HIGH
LOW
HIGH
4.332 MHz
8.664 MHz
LIMITING VALUES
In accordance with the Absolute Maximum Rating System (IEC 60134).
Notes
1.
2.
Human body model (equivalent to discharging a 100 pF capacitor through a 1.5 k
series resistor).
Machine model (equivalent to discharging a 200 pF capacitor through a 0
series resistor and 0.75
μ
H inductance).
THERMAL CHARACTERISTICS
SYMBOL
PARAMETER
CONDITIONS
MIN.
MAX.
UNIT
V
DD
V
n
supply voltage
voltage at pins 1 to 4, 7 to 10, and
13 to 16 with respect to pins 6 and 11
input current at pins 1 to 5, 7 to 11 and
13 to 16
latch-up protection current in pulsed
mode
0
0.5
6.5
V
DD
+ 0.5
≤
6.5 V
V
pins 5 and 12 are
connected to V
DD
pins 6 and 11 are
connected to ground
T
amb
=
40 to +85
°
C with
voltage limiting
2 to +10 V
T
amb
= 25
°
C with voltage
limiting
2 to +12 V
T
amb
=
40 to +85
°
C
without voltage limiting
I
i
10
+10
mA
I
lu(prot)
100
+100
mA
200
+200
mA
10
+10
mA
T
amb
T
stg
V
es
ambient temperature
storage temperature
electrostatic handling voltage
40
65
4000
500
+85
+150
+4000
+500
°
C
°
C
V
V
note 1
note 2
SYMBOL
PARAMETER
CONDITIONS
VALUE
UNIT
R
th(j-a)
thermal resistance from junction to ambient
in free air
104
K/W