lc75342m Sanyo Semiconductor Corporation, lc75342m Datasheet - Page 18

• Manufacturer Part Number: lc75342m
• Description: Single-chip Volume And Tone Control System
• Manufacturer: Sanyo Semiconductor Corporation

Bass Band Circuit
This section presents the equivalent circuit and the calculations for the external capacitors and resistors used to achieve a
center frequency of 100 Hz.
• Bass band equivalent circuit
• Sample calculation
Specifications
(1) Determine R2 from the fact that G = 20 dB.
(2) Determine C from the fact that the center frequency f0 = 100 Hz.
(3) Determine Q.
G
R3 = ———————— = —————
f 0 = ————————
C = —————— = ———————————
Q = ——— • ———
+20dB
2 f 0 R3R2
R3R2
2R3
2
= 20 LOG
2 (10
1
R3R2C1C2
G+20dB/20
Center frequency: f0 = 100 Hz
Gain at maximum boost: G = 20 dB
Let R1 = 0, R2 = 66.6 K , and C1 = C2 = C.
1
R2
R3R2
1
10
– 1)
(
1 + ——
2
2.1
2R3
R2
100 66000 3700
2 (10 – 1)
)
66000
1
LC75342, 75342M
3.7 k
0.1 µF
No. 6271-18/20