lc75421m Sanyo Semiconductor Corporation, lc75421m Datasheet - Page 20

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

(4) Bass Peaking Circuit
• Bass band equivalent circuit diagram
• Calculation example
Simulation Results
11.9 dB
10.2 dB
Specification Mean frequency: f0 = 100 Hz
8.5 dB
6.8 dB
5.1 dB
3.4 dB
1.7 dB
Setting
We obtain R3 from G = 11.9 dB.
We obtain C from mean frequency f0 = 100 Hz.
We obtain Q.
The equivalent circuit and the formula for calculating the external RC with a mean frequency of 100 Hz are shown
below.
C
G
R3
f 0
+11.9 dB
Q
2 f0 R3R2
2 10
2
R3R2
2R3
f = 100 Hz
11.88
10.38
20 LOG
1
R3R2C1C2
8.79
7.14
5.42
3.66
1.85
11.9dB/20
Gain during maximum boost: G = 11.9 dB
Let us use R1 = 0, R2 = 45.084 kΩ, and C1 = C2 = C.
R2
1
•
R3R2
–1
1
10
f = 1 kHz
2
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1
100 45084 7680
2 (3.936 – 1)
1.66
2R3
R2
45084
1
C1
7.68 K
0.082 F
R1
LC75421M
R3
R2
C2
No. 6866-20/24