TDA7478 Datasheet, PDF (1/8 Pages) STMicroelectronics – SINGLE CHIP RDS DEMODULATOR

TDA7478
SINGLE CHIP RDS DEMODULATOR
1 FEATURES
■ 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
■ RDS SIGNAL QUALITY OUTPUT
■ 4.332MHz CRYSTAL OSCILLATOR(8.664MHz
OPTIONAL)
■ LOW NOISE CMOS TECHNOLOGY
■ LOW RADIATION
2 DESCRIPTION
The TDA7478 recovers the additional inaudible RDS
information which is transmitted by FM radio broad-
casting stations and operates in accordance with the
Figure 2. Block Diagram
Figure 1. Packages
SO16
Table 1. Order Codes
Part Number
TDA7478D
E-TDA7478AD
TSSOP16
Package
SO16
TSSOP16
EBU (European Broadcasting Union) specifications.
The device is made up of two sections: a cascaded
antialiasing + switched capacitors 8^th 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 pro-
cessed by a suitable RDS decoder.
Output for RDS signal quality is also present.
C1 27pF 4.332MHz C2 47pF
4
MPX
270pF
8
FILOUT
V_S
100nF
10µF
12
VREF 3
2nd ORDER
ANTIALIASING
FILTER
8th ORDER
SC-BANDPASS
FILTER
-
+
T57
15
OSCIN
13
OSCOUT
14
OSCILLATOR &
DIVIDER
57KHz PLL
1187.5Hz
PLL
QUAL DET.
5
OSEL
9
FSEL
16
RDCL
7
N.U.
1
QUAL
POLARITY
BIPHASE DEC.
INTEGRAL
BIPHASE DEC.
0
MUX
1
DIFF. DECODER
2
RDDA
TEST LOGIC
10
TM
6
GND
November 2004
11
EXTRES
D03AU1490
Rev. 2
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