ak4141 AKM Semiconductor, Inc., ak4141 Datasheet - Page 24

• Manufacturer Part Number: ak4141
• Description: Nicam/a2/eia-j Digital Stereo Decoder
• Manufacturer: AKM Semiconductor, Inc.

(2) Gain Compensation (EQ0)
Gain Compensation is used to compensate the frequency response and the gain that is changed by Stereo Separation
Emphasis Filter. Gain Compensation is composed of the Equalizer (EQ0) and the Gain (0dB/+12dB/+24dB).
E0A1[15:0], E0A215:0], E0B1[15:0] and E0B2[15:0] bits set the coefficient of EQ0. GN1[1:0], GN2[1:0] bits set the
gain
MS0952-E-00
(Table
fs: Sampling frequency
fc
fc
K: Filter gain [dB] (Maximum +12dB)
Register setting
1
2
E0C10(E0C20))
: Pole frequency
: Zero-point frequency
E0A1[15:0], E0A2[15:0] bits =A, E0B1[13:0], E0B2[13:0] bits =B, E0C1[15:0], E0C2[15:0] bits =C
(MSB=E0A115(E0A215),E0B113(E0B213), E0C115(E0C215); LSB=E0A10(E0A20), E0B10(E0B20),
Transfer function
H(z) =
A = 10
9).
K/20
A + Cz
1 + Bz
x
(Figure
1 + 1 / tan (πfc
1 + 1 / tan (πfc
−1
−1
15)
Gain[dB]
GN1
Table 9. Gain select of gain block (x: Don’t care)
0
0
1
2
1
/fs)
/fs)
K
Figure 16. EQ0 Frequency Response
,
B =
GN0
0
1
x
1 − 1 / tan (πfc
1 + 1 / tan (πfc
fc
- 24 -
1
+12dB
+24dB
Gain
0dB
fc
1
1
/fs)
/fs)
2
,
C =10
(default)
Frequency
K/20
x
1 − 1 / tan (πfc
1 + 1 / tan (πfc
2
1
/fs)
/fs)
[AK4141]
2008/05