TFA9879 NXP Semiconductors, TFA9879 Datasheet - Page 13

• Manufacturer Part Number: TFA9879
• Description: The TFA9879 contains a processor that supports a range of sound processing featuresincluding a 5-band parametric equalizer, separate bass and treble control, a dynamicrange compressor, soft clip control and volume control
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TFA9879
Product data sheet
The transfer function of this all-pass filter is given in
A(z) is the second order filter structure. The transfer function of A(z) is given in
Equation
Z
K
Equation 5
Equation 6
The ranges of the parametric equalizer settings for each band are:
Filter coefficients need to be entered for each filter stage via the I
configure the filters (see
Figure
The relationships are symmetrical for the suppression and amplification functions. A
skewing effect can be observed at higher frequencies.
H z ( )
A z ( )
K
K
Fig 6.
−1
0
•
•
•
2
2
, K
equals one f
=
=
The gain, G, is from −30 dB to +12 dB.
The center frequency, f
The quality factor, Q, is from 0.001 to 8.
1
=
=
(
(
and K
2Q G
2Q
7,
------------------------------------------------------------------------------ -
1
1 2 ⁄
K
Figure 8
Regalia-Mitra filter flow diagram
4:
K
+
⋅
–
X(z)
1
1
can be used to calculate band suppression (G < 1) functions.
can be used to calculate band amplification (G ≥ 1) functions.
K
K
+
2
sin
⋅
K
2
=
0
(
–
and the filter parameters G, ω and Q is shown in
K
1
1
⋅
K
ω
=
–
s
All information provided in this document is subject to legal disclaimers.
(
sin
2
s
+
=
1
0
cos
)
⋅
delay period. The relationship between the programmable parameters
G
A z ( )
⁄
(
+
and
=
ω
–
(
1
ω
K
cos
2Q
)
+
G
⁄
1
Rev. 02 — 15 October 2010
)
(
Figure 9
) Z
K
ω
2Q G
+
+
⋅
1
A(z)
Section
) Z
K
sin
1 –
⋅
⋅
c
0
, is from 0.0004 ´ f
ω
2 ⁄
+
1 –
)
+
K
⋅
+
illustrate some possible equalizer band transfer functions.
G 1
+
1
sin
(
10.4.3).
1 A z ( )
≥
Z
⋅
Mono BTL class-D audio amplifier with digital input
2 –
Z
–
ω
2 –
−
)
G 1
+
<
)
+
s
½
to 0.49 ´ f
K
Equation
0
/2
s
.
3:
Equation 5
2
C-bus interface to
TFA9879
© NXP B.V. 2010. All rights reserved.
010aaa406
and
Y(z)
Equation
13 of 60
(3)
(4)
(5)
(6)
6.