TDA7340G STMicroelectronics, TDA7340G Datasheet - Page 22

• Manufacturer Part Number: TDA7340G
• Description: IC PROCESSOR AUDIO SIGNAL 44PQFP
• Manufacturer: STMicroelectronics
• Type: Car Signal Processorr

Specifications of TDA7340G

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

TDA7340G
No possibility to change the loud boost rate at a
certain volume level.
The TDA7340G implements a fully programmable
loudness control in 15 steps of 1.25dB.
It allows a customized loudness response for
each application.
The external network connected to the loudness
pins LOUD_L and LOUD_R fixes the type of loud-
ness response
BASS FILTER
Several bass filter types can be implemented.
Normally it is used the basic T-type Bandpass Filter.
Starting from the filter component values (R1 in-
ternal and R2, C1, C2 external), the centre fre-
quency Fc, the gain Av at max bass boost and
the filter Q factor are computed as follows:
Viceversa fixed Fc, Av, and R1 = 50K
typ.+/-30%), the external component values are:
22/27
1) Simple Capacitor
2)Second order Loudness (boost of low and
3)Second order decreased type Loudness
4)Second order modified type Loudness (higher
The loudness effect is only a boost of low fre-
quencies. (see Fig.20)
high frequencies).
(lower boost of low and high frequencies).
boost of low and high frequencies).
F
A
c
v
Q
2
R2 C2
C2
C1
R2 C1
R2 C1
R1 R2 C1 C2
A
2
v
Q Q C1
R1 R2 C1 C2
R2 C1
A
1
1
v
R2 C2
R1 Q
R2 C2
Q Q
1
R1 C1
(internal
TREBLE STAGE
The Treble stage is a simple high pass filter which
time constant is fixed by internal resistor (50Kohm
typ) and an external capacitor connected between
pins TREB_R/TREB_L and Ground.
IN-OUT PINS
The multiplexer output is available at OUT_R and
OUT_L pins for optional connection of external
graphic equalizer (TDA7316/TDA7317), surround
chip (TDA7346) etc.
The signal is fed in again at pins IN_L and IN-R.
In case of application without external devices the
pins OUT_L/OUT_R and IN_L/IN_R cannot be
short circuited, but must be decoupled via capaci-
tor, necessary to avoid signal DC jumps, generat-
ing "Clicking" output noise.
The input impedance of the next volume stage is
35Kohm typical (minimum 24Kohm). A capacitor
no lower than 1uF should be used.
INPUT SELECTOR
The multiplexer selector can choose one of the
following inputs:
The signal fed to the input pins must be decou-
pled via series capacitors. The minimum allowed
value depends on the correspondent input imped-
ance.
For the CD diff input (Zi=10Kohm worst case ) a
Cin=4.7uF is recommended.
For the other inputs (70Kohm worst case, except
PHONE 14Kohm worst case but speech audio
band) a Cin=1uF is recommended.
- a differential CD stereo input.
- an FM stereo input coming from the on chip-
- a Cassette stereo input.
- a Telephone Differential mono input.
- an AM stereo input or alternatively (sw pro-
stereo decoder.
grammable) an AM mono + BEEP mono.
R2
2
A
C1 F
v
1
c
Q Q
A
v
1
Q