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TDA7419

5.10 Spectrum Analyzer

A fully integrated seven-band spectrum analyzer with programmable quality factor is present. The spec-

trum analyzer consists of seven band pass filters with rectifier and sample capacitor that stores the max-

imum peak signal level since the last read cycle. This peak signal level can be read by a microprocessor

at the SAout-pin. To allow easy interfacing to an analog port of the microprocessor, the output voltage at

this pin is referred to device ground.

The microprocessor starts a read cycle with the negative going clock edge at the SAclk input. On the fol-

lowing positive clock edges, the peak signal level for the band pass filters is subsequently switched to

to be held at high potential. Figure 20 shows the block diagram and figure 21 illustrates the read cycle

timing of the spectrum analyzer.

Figure 20. Spectrum analyzer block diagram

Figure 21. Timing of the spectrum analyzer