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◆ 10% Tested for Quiescent Current at 20V
◆ Maximum Input Current of 1mA at 18V Over Full Package Temperature Range, 100nA at 18V and 25
℃
◆ Break-Before-Make Switching Eliminates Channel Overlap
3.5.8 function introduction to SAA6588
1. DESCRIPTION
Today most FM radio stations in Europe and meanwhile also many FM/AM radio broadcasting stations in
the USA transmit the inaudible European RDS (Radio Data System) or the USA RBDS (Radio Broadcast
Data System) informations respectively. Likewise nowadays receivers, most car radios and also some home
and portable radios on the market include at least some of the RDS features.
The RDS/RBDS system offers a large range of applications by its many functions to be implemented. For
car radios the most important are:
◆ Program Service (PS) name
◆ Traffic Program (TP) identification
◆ Traffic Announcement (TA) signal
◆ Alternative Frequency (AF) list
◆ Program Identification (PI)
◆ Enhanced Other Networks (EON) information.
The RDS/RBDS pre-processor is a CMOS device that integrates all RDS/RBDS relevant functions in one
chip. The IC contains filtering and demodulation of the RDS/RBDS signal, symbol decoding, block
synchronization, error detection, error correction and additional detectors for multi-path, signal quality and
audio signal pauses. The pre-processed RDS/RBDS information is available via the I2C-bus.
The RDS/RBDS pre-processor replaces a number of Ics and peripheral components used nowadays in
car radio concepts with RDS or RBDS features. The integration of the relevant RDS/RBDS data processing
functions provides, in an economic manner, high performance of RDS/RBDS processing and reduces the
real-time requirements for the main radio microcontroller considerably. In addition it simplifies the
development of the RDS specific software for the main controller of the radio set.
Compared with standard radio systems, RDS/RBDS controlled radio systems additionally require an
RDS/RBDS demodulator with a 57 kHz band-pass filter, information about the current reception situation
(reception quality, multi-path disturbance etc.), and additional microcontroller power for RDS/RBDS data
processing, decoding and radio control.
The new RDS/RBDS pre-processor includes all these specific functions and meets all requirements of a
high end RDS/RBDS radio. Moreover the timing requirements of the set controller, regarding RDS/RBDS data
processing are reduced due to the integration of decoder functions, so that the development of radio control
software can be concentrated specifically on radio set features.
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