TDA7406TR STMicroelectronics, TDA7406TR Datasheet - Page 24

• Manufacturer Part Number: TDA7406TR
• Description: IC PROCESSOR CAR SIGNAL 44-TQFP
• Manufacturer: STMicroelectronics
• Type: Car Signal Processorr

Specifications of TDA7406TR

• Applications: Automotive Systems
• Mounting Type: Surface Mount
• Package / Case: 44-TQFP, 44-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Description of the audioprocessor part
4.8
4.8.1
24/64
cutoff frequencies are not equal but shifted by the factor 1.125 to get a flat frequency
response (see
Figure 14. Subwoofer Application with Lowpass @ 80/120/160Hz and HighPass @
Spectrum analyzer
A fully integrated seven band spectrum analyzer with programmable quality factor is present
in the IC
The spectrum analyzer consists of seven band pass filters with a rectifier and sample
capacitor which stores the maximum peak signal level since the last read cycle. This peak
signal level can be read by a microprocessor at the SA
microprocessor analog port, the output voltage at this pin is referred to device ground.
The microprocessor starts a read cycle when there is a clock edge going negative at the
SA
filters is subsequently switched to SA
t
A reset of the sample capacitors is induced whenever SA
Note that a proper reset requires the clock signal SA
shows the block diagram and
analyzer.
The spectrum analyzer minimum repeat time is 50ms.
Spectrum Analyzer Filters
Each filter is realized as a switched capacitor with a 2nd order frequency response. The
center frequency of the filter stages are: 62,157, 396, 1K, 2.51K, 6.34k and 16kHz. It is
possible to choose between two different filter quality factors: 1.8 and 3.5.
SAdel
clk
.
input. On the following positive clock edges, the peak signal level for the band pass
dB
(Figure
-10.0
-20.0
-30.0
-40.0
-50.0
0.0
10.0
90/135/180Hz
Figure
15).
14).
Figure 16
100.0
out
. Each analog output data is valid after the time
illustrates the read cycle timing of the spectrum
Hz
clk
1.0K
to be held at high potential. Figure 15
out
clk
pin. To allow easy interfacing to a
remains high for the time t
10.0K
TDA7406
intres
.