SAA6588/V2,112 NXP Semiconductors, SAA6588/V2,112 Datasheet - Page 6

• Manufacturer Part Number: SAA6588/V2,112
• Description: IC RDS/RBDS PRE-PROCESSOR 20DIP
• Manufacturer: NXP Semiconductors

Specifications of SAA6588/V2,112

• Function: Pre-Processor
• Frequency: 57kHz
• Package / Case: 20-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 935261513112; SAA6588N; SAA6588N

Philips Semiconductors
FUNCTIONAL DESCRIPTION
General
The following functions are performed by the SAA6588:
The block diagram of the RDS/RBDS pre-processor is
shown in Fig.1. For the application of the device only a few
external components are required. The pre-processors
functional blocks are described in the following sections.
RDS/RBDS signal demodulation
B
The band-pass filter has a centre frequency of 57 kHz.
It selects the RDS/RBDS sub-band from the multiplex
signal MPX and suppresses the audio signal components.
The filter block contains an analog anti-aliasing filter at the
input followed by an 8th order switched capacitor
band-pass filter and a reconstruction filter at the output.
C
The comparator digitizes the output signal from the 57 kHz
band-pass filter for further processing by the digital
RDS/RBDS demodulator. To attain high sensitivity and to
avoid phase distortion, the comparator input stage
contains an automatic offset compensation.
2002 Jan 14
AND
LOCKED COMPARATOR
Selection of the RDS/RBDS signal from the MPX input
signal
57 kHz carrier regeneration
Demodulation of the RDS/RBDS signal
Symbol decoding
RDS/RBDS block detection
Error detection and correction of transmission errors
Fast block synchronization and synchronization control
Detection of multi-path distortion and audio signal
pauses
Determination of the signal quality
Mode control of processing and RDS/RBDS data output
via I
Sensing of pause and multi-path, information via extra
output pins.
RDS/RBDS pre-processor
-
PASS FILTER
2
C-bus interface
6
D
The demodulator provides all functions of the SAA6579
but has improved performance under weak signal
conditions.
The demodulator includes:
The RDS/RBDS demodulator recovers and regenerates
the continuously transmitted RDS/RBDS data stream out
of the multiplex signal (MPX) and provides the internal
signals clock (RDCL) and data (RDDA) for further
processing by the RDS/RBDS decoder block.
RDS/RBDS data processing
The RDS/RBDS data processing of the pre-processor
handles the complete processing and decoding of the
continuous serial RDS/RBDS demodulator output data
stream.
Different data processing modes are software controllable
by the external main controller via I
Processed RDS/RBDS data blocks, decoder status
information and signal quality information are also
available via the I
RDS/RBDS
The RDS/RBDS decoder contains:
EMODULATION
57 kHz carrier regeneration from the two sidebands
(Costas loop)
Symbol integration over one RDS clock period
Bi-phase symbol decoding
Differential decoding
Synchronization of RDS/RBDS output data with clock.
RDS/RBDS block detection
Error detection and correction
Synchronization
Flywheel for synchronization hold
Bit slip correction
Data processing control
RDS/RBDS data output.
DECODER
2
C-bus.
2
C-bus.
Product specification
SAA6588