SGS Thomson Microelectronics TDA7331D, TDA7331 Datasheet

SINGLE CHIP RDS DEMODULATOR + FILTER
VERYHIGH RDS DEMODULATION QUALITY WITH IMPROVED DIGITAL SIGNAL PROC­ESSING
HIGH PERFORMANCE, 57KHz BANDPASS FILTER (8th ORDER)
PURELY DIGITAL RDS DEMODULATION WITHOUTEXTERNAL COMPONENTS
ARI INDICATION AND RDS SIGNAL QUAL­ITY OUTPUTS
4.332MHzCRYSTALOSCILLATOR (8.664 and 17.328MHz SELECTABLE OP­TIONS)
LOW NOISE CMOS TECHNOLOGY LOW RADIATION
TDA7331
DIP20 SO20
ORDERING NUMBERS:
TDA7331 TDA7331D
DESCRIPTION
The TDA7331, an improved version of TDA7330B, recovers the additional inaudible RDS informationwhich is transmittedby FM radio broadcasting stations and operates in accord­ance with the EBU (European Broadcasting Un­ion) specifications.
The device is made up of two sections: a cas-
BLOCK DIAGRAM and TESTCIRCUIT
FILOUT
1
2nd ORDER
ANTIALIASING
FILTER
4
16
2VREF
8th ORDER
SC-BANDPASS
FILTER
-
+
MPX
V
S
100nF
10µF
270pF
caded antialiasing + switched capacitors band­pass filter for precise RDS band selection and a demodulatingsection that performs the extraction od RDS data stream (RDDA) and clock (RDCL), to be furher processed by a suitable RDS de­coder.
Outputs for RDS signal quality and ARI indication are also present.
4.332MHz C2 47pFC1 27pF
T57
11
57KHz PLL
FAST
INDICATOR
POLARITY
BIPHASEDEC.
INTEGRAL
BIPHASEDEC.
OSCILLATOR
ARI
DIVIDER
OSCOUTOSCIN 910
3
&
1187.5Hz PLL
QUAL DET.
0
MUX
1
DIFF. DECODER
TEST LOGIC
OSEL
18
FSEL
12
RDCL
15
ARI
14
QUAL
13
RDDA
19
TM
February 1998
5
GND N.C.
6,7,8,17
EXTRES
20
D97AU686B
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TDA7331
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
V
T
op
T
stg
PIN FUNCTION
Nopin Name Functional description
1 MPX RDS inputsignal 2 VREF Reference voltage 3 OSEL Oscillator selector pin: - open, or closed to Vs = quartz oscillator
4 FILOUT Filter output 5 GND Ground
6 nc Not connected
7 nc Not connected 8 nc Not connected
9 OSCOUT Oscillator output 10 OSCIN Oscillator input 11 T57 Testing output pin: 57kHz clock output 12 RDCL RDS clock output 1187.5Hz 13 RDDA RDS dataoutput 14 QUAL Output for signal quality indication (High = good) 15 ARI Output for ARI indication: - high whenRDS+ARI arepresent
16 Vs Supply voltage 17 nc Not connected 18 FSEL Frequency selector pin: - 100K to V
19 TM Test mode pin: - open = normal operation
20 EXTRES Reset pin: - open = run mode
Supply Voltage 7 V
S
Operating Temperature Range -40 to 85 Storage Temperature -55 to 150
- closed to GND = external driven
- high when only ARI is present
- low when only RDS is present
- undefined when nos signal is present
= 17.328MHz
S
S
= testmode
S
= 8.664MHz
- closed to V
-closed to V
- open = 4.332MHz
- closed to V
= reset condition
S
C
°
C
°
PIN CONNECTION
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MPX VREF OSEL
FILOUT
GND
N.C. N.C. N.C.
OSCOUT
1 2 3 4 5 6 7 8 9 RDCL
OSCIN 10 T5711
D97AU687
19 18 17 16 15 14 13 12
EXTRES20 TM FSEL N.C. V
S
ARI QUAL RDDA
TDA7331
THERMAL DATA
Symbol Description DIP20 SO20 Unit
R
th j-amb
Thermal Resistance Junction-Ambient Max 100 200
C/W
°
ELECTRICALCHARACTERISTICS (T
=25°C, VS=5V, unlessotherwisespecified).
amb
Symbol Parameter Test Condition Min. Typ. Max. Unit
V
S
I
S
Supply voltage 4.5 5 5.5 V Supply current 7.5 11.0 mA
FILTER
f
C
BW 3dBBandwidth 2.5 3 3.5 kHz
G Gain f = 57kHz 18 20 22 dB
A Attenuation
R
R
L
S/N Signal to noise ratio V
V
IN
V
REF
Center frequency 56.5 57 57.5 kHz
4kHz 18 22 dB
∆f±
f = 38kHz 50 60 dB f = 67kHz 35 45 dB
Input impedance of MPX 80 120 150 K
I
Load impedance on FILOUT 1 M
=3mV
IN
RMS
30 40 dB
MPX input signal f = 19kHz; T3 40dB(1)
f = 57kHz (RDS+ ARI)
Reference VS/2 V
100050mV
mV
DEMODULATOR
Input pins (EXTRES, FSEL, TM) all with internal pull down resistor Input pin (OSEL) with internal pull up resistor
I
PD
I
PU
V
IH
V
IL
Input Current VIN= 5V (pull-down input) 15 30 Input Current VIN= 0V (pull-up input) -25 -10 Input voltage high 0.7⋅VS0.8⋅V
S
Input voltage low 0.2 VS0.3V
S
Output pins (RDCL, RDDA, ARI, QUAL, T57)
V
OH
V
OL
Ouput voltage high IL= 0.5mA 4 4.6 V Output voltage low IL= 0.5mA 0.4 1 V
OSCILLATOR
VCLL Input level OSCIN pin OSEL= open circuit 1 V
VCLH Input level OSCIN pin OSEL= open circuit 4 V
Amplitude OSCOUT OSEL= open circuit 4.5 V
V
PP
Amplitude OSCIN (for external drive)
(1) The 3rd harmonic (57kHz) must be less than -40dB with respect to the input signal plus gain.
OSEL = GND, f = 4.332MHz
OSEL = GND, f = 8.664MHz
OSEL = GND, f = 17.328MHz
100 mVpp
120 mVpp
150 mVpp
µ µ
RMS RMS
A
A V V
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TDA7331
Figure 1. RDS timing diagram
CLOCK
LINE
DATA
LINE
OUTPUT TIMING
The RDS (1187.5Hz) output clock on RDCL line is synchronizedto 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. 1) Whichever clock edge is used by the decoder (rising or falling edge) the data will remain valid for 416.7 µsec after the clock transition.
OSCILLATORCONTROLS (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 followings table for reference:
Crystal FSEL (pin configuration)
4.332MHz
8.664MHz
17.328MHz
connected to GND or open
connected toVs
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.
Suggestedvalues of C1 and C2 are shown in the followingtable:
Crystal C1 C2
4.332MHz
8.664MHz
17.328MHz
27pF 27pF 27pF
47pF
-
-
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DIP20 PACKAGE MECHANICAL DATA
TDA7331
DIM.
MIN. TYP. MAX. MIN. TYP. MAX.
a1 0.254 0.010
B 1.39 1.65 0.055 0.065
b 0.45 0.018
b1 0.25 0.010
D 25.4 1.000 E 8.5 0.335
e 2.54 0.100
e3 22.86 0.900
F 7.1 0.280
I 3.93 0.155
L 3.3 0.130
Z 1.34 0.053
mm inch
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TDA7331
SO20 PACKAGEMECHANICAL DATA
DIM.
MIN. TYP. MAX. MIN. TYP. MAX.
A 2.65 0.104 a1 0.1 0.3 0.004 0.012 a2 2.45 0.096
b 0.35 0.49 0.014 0.019
b1 0.23 0.32 0.009 0.013
C 0.5 0.020 c1 45 (typ.)
D 12.6 13.0 0.496 0.512
E 10 10.65 0.394 0.419
e 1.27 0.050
e3 11.43 0.450
F 7.4 7.6 0.291 0.299
L 0.5 1.27 0.020 0.050
M 0.75 0.030
S 8 (max.)
mm inch
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TDA7331
Information furnished is believed to be accurate and reliable.However, SGS-THOMSON Microelectronicsassumes no responsibility for the consequences of use of such information nor for any infringementof patentsor other rights of third parties which may result fromits use. No license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specification men­tioned in this publication are subject to change without notice.This publication supersedes and replaces all information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without ex­press written approval of SGS-THOMSON Microelectronics.
1998 SGS-THOMSON Microelectronics – Printed in Italy – All RightsReserved
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