STMICROELECTRONICS TDA7479_04

TDA7479
SINGLE CHIP RDS DEMODULATOR + FILTER
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FEATURES
Figure 1. Packages
VERY HIGH RDS DEMODULATION QUALITY
WITH IMPROVED DIGITAL SIGNAL
PROCESSING
HIGH PERFORMANCE, 57KHz BANDPASS
FILTER (8th ORDER)
FILTER ADJUSTMENT FREE AND WITHOUT
EXTERNAL COMPONENTS
PURELY DIGITAL RDS DEMODULATION
WITHOUT EXTERNAL COMPONENTS
ARI (SK INDICATION) AND RDS SIGNAL
QUALITY OUTPUT
4.332MHz CRYSTAL OSCILLATOR(8.664 and
17.328MHz OPTIONAL)
LOW NOISE CMOS TECHNOLOGY
LOW RADIATION
SO16
TSSOP16
Table 1. Order Codes
Part Number
Package
TDA7479D
SO16
TDA7479AD
TSSOP16
EBU (European Broadcasting Union) specifications.
The device is made up of two sections: a cascaded
antialiasing + switched capacitors 8th 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.
DESCRIPTION
The TDA7479 recovers the additional inaudible RDS
information which is transmitted by FM radio broadcasting stations and operates in accordance with the
Outputs for RDS signal quality and ARI indication are
also present.
Figure 2. Block Diagram
C1 27pF
T57
4.332MHz
OSCIN
OSCOUT
13
15
C2 47pF
14
4
MPX
2nd ORDER
ANTIALIASING
FILTER
270pF
5
OSCILLATOR &
DIVIDER
9
16
FILOUT
8th ORDER
SC-BANDPASS
FILTER
8
1187.5Hz
PLL
57KHz PLL
7
1
FAST ARI
INDICATOR
12
VS
QUAL DET.
OSEL
FSEL
RDCL
ARI
QUAL
100nF
VREF
-
3
+
POLARITY
BIPHASE DEC.
0
1
10µF
MUX
DIFF. DECODER
10
INTEGRAL
BIPHASE DEC.
6
GND
December 2004
2
TEST LOGIC
RDDA
TM
11
EXTRES
D97AU751A
Rev. 6
1/8
TDA7479
Table 2. Pin Description
No pin
Name
1
QUAL
Description
2
RDDA
RDS data output
3
VREF
Reference voltage
Output for signal quality indication (High = good)
4
MPX
RDS input signal
5
OSEL
Oscillator selector pin:
- open, closed to VS = quartz oscillator
- closed to GND=external driven
6
GND
Ground
7
ARI
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
8
FILOUT
9
FSEL
10
TM
11
EXTRES
12
VS
13
OSCIN
14
OSCOUT
15
T57
16
RDCL
Filter output
Frequency selector pin:
-100K to VS = 17.328MHz
- open = 4.332MHz
- closed to VS = 8.664MHz
Test mode pin: - open = normal operation - closed to VS = testmode
Reset pin: - open=run mode - closed to VS = reset condition
Supply voltage
Oscillator input
Oscillator output
Testing output pin: 57kHz clock output
RDS clock output 1187.5Hz
Figure 3. Pin Connection (Top view)
QUAL
1
16
RDCL
RDDA
2
15
T57
VREF
3
14
OSCOUT
MPX
4
13
OSCIN
OSEL
5
12
VS
GND
6
11
EXTRES
ARI
7
10
TM
FILOUT
8
9
FSEL
D97AU752
Table 3. Thermal Data
Symbol
Rth j-case
2/8
Description
Thermal Resistance Junction-case Max.
SO16
TSSOP16
Unit
200
160
°C/W
TDA7479
Table 4. Absolute Maximum Ratings
Symbol
Parameter
Value
Unit
VS
Supply Voltage
-0.3 to 7
V
Top
Operating Temperature Range
-40 to 85
°C
Tstg
Storage Temperature
-55 to 150
°C
Table 5. Electrical Characteristcs
(Tamb = 25°C, VS = 5V, unless otherwise specified)
Symbol
Parameter
VS
Supply voltage
IS
Supply current
Test Condition
Min.
Typ.
Max.
Unit
4.5
5
5.5
V
7.5
11.0
mA
FILTER
fC
BW
Center frequency
56.5
57
57.5
kHz
3dB Bandwidth
2.5
3
3.5
kHz
22
G
Gain
f = 57kHz
18
20
A
Attenuation
∆f ± 4kHz
18
22
dB
f = 38kHz
50
60
dB
f = 67kHz
35
45
dB
120
RI
Input impedance of MPX
80
RL
Load impedance on FILOUT
1
S/N
Signal to noise ratio
VIN
MPX input signal
VIN = 3mVRMS
30
150
40
dB
1000
50
f = 19kHz; T3 ≤ 40dB
f = 57kHz (RDS+ ARI)
RDS Detection Sensitivity
1
SARI
ARI Detection Sensitivity
3
VREF
Reference
KΩ
MΩ
(1)
SRDS
dB
mVRMS
mVRMS
mVrms
mVrms
VS/2
V
DEMODULATOR
Input pins (EXTRES, FSEL, TM)
Input pin (OSEL)
all with internal pull down resistor
with internal pull up resistor
IPD
Input Current
VIN = 5V (pull-down input)
VIN = 0V (pull-up input)
IPU
Input Current
VIH
Input voltage high
VIL
Input voltage low
15
30
µA
-25
-10
µA
0.7 · VS 0.8 · VS
V
0.2 · VS 0.3 · VS
V
Output pins (RDCL, RDDA, ARI, QUAL, T57)
VOH
Ouput voltage high
IL = 0.5mA
VOL
Output voltage low
IL = 0.5mA
4
4.6
0.4
V
1
V
1
V
OSCILLATOR
VCLL
Input level OSCIN pin
OSEL = open circuit
VCLH
Input level OSCIN pin
OSEL = open circuit
Amplitude OSCOUT
OSEL = open circuit
4.5
V
Amplitude OSCIN
(for external drive)
OSEL = GND, f = 4.332MHz
OSEL = GND, f = 8.664MHz
100
120
mVpp
mVpp
OSEL = GND, f = 17.328MHz
150
mVpp
VPP
4
V
(1) The 3rd harmonic (57kHz) must be less than -40dB with respect to the input signal plus gain.
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TDA7479
Figure 4. RDS timing diagram
CLOCK
LINE
DATA
LINE
3
OUTPUT TIMING
The RDS (1187.5Hz) output clock on RDCL line is synchronized to the incoming data. According to the internal
PLL lock condition data change can result on the falling or on the rising clock edge. (see Fig. 4)Whichever clock
edge is used by the decoder (rising or falling edge) the data will remain valid for 416.7 µs after the clock transition.
4
OSCILLATOR CONTROLS (FSEL, OSEL)
Three different crystal frequencies can be used. The adaption of the internal clock divider to the external crystal
is achieved via the input pin FSEL. See the following table for reference:
Table 6.
Crystal
4.332MHz
8.664MHz
17.328MHz
FSEL (pin configuration)
connected to GND or openconnected to Vs external resistor of 100K to Vs
A special mode is introduced to reduce EMI. With pin OSEL connected to GND the internal oscillator is switched
off and an external sinusoidal frequency could be applied on OSCIN. The peak to peak voltage of this signal
can be reduced down to 60mV.
In this mode the frequency selection via FSEL is still active.
Suggested values of C1 and C2 are shown in the following table:
Table 7.
4/8
Crystal
C1
C2
4.332MHz
8.664MHz
17.328MHz
27pF
27pF
27pF
47pF
-
TDA7479
Figure 5. SO16 Mechanical Data & Package Dimensions
mm
inch
DIM.
MIN.
TYP.
MAX.
MIN.
TYP.
MAX.
A
2.35
2.65
0.093
0.104
A1
0.10
0.30
0.004
0.012
B
0.33
0.51
0.013
0.200
C
0.23
0.32
0.009
0.013
D (1)
10.10
10.50
0.398
0.413
E
7.40
7.60
0.291
0.299
e
1.27
0.050
H
10.0
10.65
0.394
0.419
h
0.25
0.75
0.010
0.030
L
0.40
1.27
0.016
0.050
k
ddd
OUTLINE AND
MECHANICAL DATA
0˚ (min.), 8˚ (max.)
0.10
0.004
(1) “D” dimension does not include mold flash, protusions or gate
burrs. Mold flash, protusions or gate burrs shall not exceed
0.15mm per side.
SO16 (Wide)
0016021 C
5/8
TDA7479
Figure 6. TSSOP16 Mechanical Data & Package Dimensions
mm
inch
DIM.
MIN.
TYP.
A
MAX.
MIN.
TYP.
1.200
A1
0.050
A2
0.800
b
MAX.
0.047
0.150
0.002
1.050
0.031
0.190
0.300
0.007
0.012
c
0.090
0.200
0.005
0.009
D (1)
4.900
5.000
5.100
0.114
0.118
0.122
E
6.200
6.400
6.600
0.244
0.252
0.260
E1 (1) 4.300
4.400
4.500
0.170
0.173
0.177
e
L
L1
k
aaa
1.000
0.650
0.450
0.600
OUTLINE AND
MECHANICAL DATA
0.006
0.039
0.041
0.026
0.750
0.018
1.000
0.024
0.030
0.039
0˚ (min.) 8˚ (max.)
0.100
0.004
Note: 1. D and E1 does not include mold flash or protrusions.
Mold flash or potrusions shall not exceed 0.15mm
(.006inch) per side.
TSSOP16
(Body 4.4mm)
0080338 (Jedec MO-153-AB)
6/8
TDA7479
Table 8. Revision History
Date
Revision
Description of Changes
September 2004
4
First Issue in EDOCS dms.
November 2004
5
Add in the table 5 “RDS and ARI Detection Sensitivity” parameters.
2 December 2004
6
Errata corrige of the Order Codes table.
7/8
TDA7479
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of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted
by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject
to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not
authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.
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