TDA7317 - ST Microelectronics

TDA7317 FIVE BANDS DIGITAL CONTROLLED GRAPHIC EQUALIZER

The TDA7317 is a monolithic, digitally controlled graphic equalizer realized in BiCMOS mixed technology. The stereo signal, before any filtering, can be atBLOCK DIAGRAM SDIP30 ORDERING NUMBER: TDA7317 tenuated up to -17.625dB in 0.375dB step. All the functions can be programmed via serial bus making easy to build a µP controlled system. Signal path is desi.

Features

of each band pass filter are reported: fo = center frequency Gv = gain/loss at the center frequency fo Gv = 20log(Av) Fig. 1 Q= fo f2 − f1 where f2, f1 = 3dB Bandwidth limits. Av = (R2 ⋅ C2 ) + (R2 ⋅ C1 ) + (R1 ⋅ C1 ) (R2 ⋅ C1 ) + (R2 ⋅ C2 ) Q= fo = √  (R1 ⋅ C1 ⋅ R2 ⋅ C2 ) (R2 ⋅C1 ) + (R2 ⋅ C2 ) 1 2π ⋅  √ (R1 ⋅ R2 ⋅ C1 ⋅ C2) If C1 is fixed, then: C2 = R2 = Q2 Av − 1 − Q2 1 2 π ⋅ C1 ⋅ fo ⋅ R1 = (Av −1 ) ⋅ Q (Av − 1 − Q2) ⋅ R2 ⋅ C1 (Av − 1)2 Av − 1 − Q2 Likewise, the components’values can be determined by fixing one of the other three parameters. Referring.