lc75421m Sanyo Semiconductor Corporation, lc75421m Datasheet - Page 18

• Manufacturer Part Number: lc75421m
• Description: Electronic Volume Controller For Cars
• Manufacturer: Sanyo Semiconductor Corporation

Bass Shelving Circuit
• Bass band equivalent circuit diagram
• Calculation example 1
Simulation Results
Specification Mean frequency: f0 = 40 Hz
14 dB
12 dB
10 dB
Setting
We obtain R3 from G = 14 dB.
We obtain C2 from mean frequency f0 = 40 Hz.
8 dB
6 dB
4 dB
2 dB
The equivalent circuit and calculation formula during boost are shown below.
C2
G
R3
f 0
+14 dB
2
(2 f0)
10
f = 100 Hz
20 LOG
13.55
11.73
G/20
R2
7.89
5.94
3.97
1.99
R3R2C1C2
9.8
Gain during maximum boost: G
Let us use R1 = 0 kΩ, R2 = 45.054 kΩ, C1 = 2.2 µF, and C1 >> C2.
2
–1
1
R2R3 C1
1
10
f = 1 kHz
5.01 – 1
3.65
3.51
3.31
2.55
1.92
1.07
45054
R2
3
R3
(2
R3
40)
11 K
2
45054 11000 (2.2 10
C1
+ 14 dB
1
R1
LC75421M
= 14 dB
R3
R2
–6
)
C2
0.015 F
No. 6866-18/24