TDA7439_08 Datasheet, PDF (9/23 Pages) STMicroelectronics – Three-band digitally-controlled audio processor

TDA7439
Application suggestions
Transposing and solving for the external component values we get:
C1 = -------------^A-----^V----–-----¹--------------
2 ⋅ π ⋅ Fc ⋅ Ri ⋅ Q
C2 = ------^Q----²-----^â‹---^C----¹-------
A_V – 1 – Q²
R2 = -₂----_â‹---_π-----_â‹---_C-----^A1----^V-_â‹---_F^–----_c-¹---_â‹--–-₍---_AQ----_V-²---–-----₁----₎---_â‹---_Q---
3.1.2
Treble stage
The treble stage is a high-pass filter whose time constant is fixed by an internal resistor
(25 kΩ typically) and an external capacitor connected between treble pins and ground.
Typical responses are shown in Figure 10 and Figure 11.
3.2
Pin CREF
The suggested value of 10 µF for the reference capacitor (C_REF), connected to pin CREF,
can be reduced to 4.7 µF if the application requires faster power-on.
3.3
Electrical characteristics
Figure 5. THD vs frequency
Figure 6. THD vs R_LOAD
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