TDA7319 Datasheet, PDF (4/16 Pages) STMicroelectronics – 3 BAND DIGITAL CONTROLLED AUDIO PROCESSOR

TDA7319
ELECTRICAL CHARACTERISTICS (continued)
Symbol
Parameter
Test Condition
Min.
GENERAL
eNO
Output Noise
E_t
Total Tracking Error
S/N
Signal to Noise Ratio
S_C
Channel Separation
d
Distortion
BUS INPUTS
V_il
Input Low Voltage
Vih
Input High Voltage
I_in
Input Current
V_O
Output Voltage SDA
Acknowledge
All Gains 0dB (B = 20 to 20kHz flat)
AV = 0 to -24dB
AV = -24 to -47dB
All Gains = 0dB; VO = 1Vrms
80
A_V = 0; V_in = 1V_rms
3
Vin = 0.4V
-5
I_O = 1.6mA
Note 1: the device is functionally good at Vs = 5V. A step down, on VS, to 4V does’t reset the device.
Typ.
5
0
0
106
100
0.01
0.4
Max.
15
1
2
0.08
1
5
0.8
Unit
µV
dB
dB
dB
dB
%
V
V
µA
V
APPLICATION SUGGESTIONS
The first and the last stages are volume control
blocks. The control range is 0 to -47dB (mute)
with a 1dB step.
The very high resolution allows the implementation
of systems free from any noisy acoustical effect.
The TDA7319 audioprocessor provides 3 bands
tones control.
The fig.1 refers to 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. boost and the fil-
ter Q factor are computed as follows:
F_C =
1
2 ⋅ π ⋅√Ri,R2,C1,C2
Bass, Middle Stages
The Bass and the middle cells have the same
structure.
The Bass cell has an internal resistor Ri = 44KΩ
typical.
The Middle cell has an internal resistor Ri = 25KΩ
typical.
Several filter types can be implemented, connect-
ing external components to the Bass/Middle IN
and OUT pins.
Figure 1.
Ri internal
IN
OUT
C₁
C₂
R₂
D95AU313
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A_V
=
R2
C2 + R2 C1 + Ri
R2 C1 + R2 C2
C1
Q
=
√RiR2+C1C2
R2 C1 + R2 C2
Viceversa, once Fc, Av, and Ri internal value are
fixed, the external components values will be:
C1
=
2
A_V
⋅π⋅
−1
R_i ⋅
Q
C2
=
Q² ⋅ C1
A_V − 1 Q²
R2
=
2
⋅
π
⋅
A_V − 1
C1 ⋅ F_C
− Q²
⋅ (A_V
−
1)
⋅Q
Treble Stage
The treble stage is a high pass filter whose time
constant is fixed by an internal resistor (25KΩ
typical) and an external capacitor connected be-
tween treble pins and ground
Typical responses are reported in Figg. 10 to 13.
CREF
The suggested 10µF reference capacitor (CREF)
value can be reduced to 4.7µF if the application
requires faster power ON.