TDA7460ND STMicroelectronics, TDA7460ND Datasheet - Page 16

• Manufacturer Part Number: TDA7460ND
• Description: IC PROCESSOR CAR RAD SGNL SO-20
• Manufacturer: STMicroelectronics
• Type: Car Signal Processorr

Specifications of TDA7460ND

• Applications: Automotive Systems
• Mounting Type: Surface Mount
• Package / Case: 20-SOIC (7.5mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Description of the audio processor part
4.1.2
4.1.3
4.2
16/49
Input stages
Most of the input circuits are the same as in preceding ST audioprocessors with exception of
the CD inputs (see
having a significant high source impedance which affects strongly the common-mode
rejection of the normal differential input stage. The additional buffer of the CD input avoids
this drawback and offers the full common-mode rejection even with those CD players.
The TDA7460ND can be configured with an additional input; if the AC coupling before the
speaker stage is not used (bit 7 in subaddress 5 set to "1") ACINL and ACINR pins can be
used as an additional stereo input.
AutoZero
In order to reduce the number of pins there is no AC coupling between the In-Gain and the
following stage, so that any offset generated by or before the In-Gain stage would be
transferred or even amplified to the output.
To avoid that effect a special offset cancellation stage called AutoZero is implemented.To
avoid audible clicks the audioprocessor is muted before the loudness stage during this time.
In some cases, for example if the µP is executing a refresh cycle of the I
programming, it is not useful to start a new AutoZero action because no new source is
selected and an undesired mute would appear at the outputs. For such applications the
TDA7460ND could be switched in the "Auto Zero Remain" mode (Bit 6 of the subaddress
byte). If this bit is set to high, the DATABYTE 0 could be loaded without invoking the
AutoZero and the old adjustment value remains.
Figure 4.
Mixing stage
This stage offers the possibility to mix the internal beep or the phone signal to any other
source. Due to the fact that the mixing stage is also located behind the In-Gain stage fine
adjustments of the main source level can be done in this way.
Input stages
CASSETTE
Figure
PH_GND
CDGND
PHONE
MPX
CD
AM
4.).In the meantime there are some CD players in the market
100K
100K
100K
100K
STEREODECODER
15K
15K
15K
15K
+
+
15K
15K
-
-
15K
15K
D97AU633A
IN GAIN
2
C bus
TDA7460ND