LV1115 Datasheet, PDF (12/15 Pages) Sanyo Semicon Device – Surround Processor ICs for Electronic Volume Control

LV1115/1115M
Bass Band Circuit: The equivalent circuit and the formula for calculating the external RC with a mean frequency of
100Hz are shown below.
• Calculation example 1: specification
Mean frequency: f0 = 100Hz
Gain during maximum boost: G_+20dB = 20dB
Let us use R1 = 0kΩ and R2 = 66.7kΩ, and C1 = C2 = C.
+
-
R1
R2
We obtain R2 from G = 20dB
C1
C2
R2
G = 20 × Log₁₀ 1+
2R3
R3
R2
R3 = _{2 (10G+20dB/20 - 1)} =
66700
2 (10 - 1)
≈3.6kΩ
We obtain C from mean frequency f0 = 100Hz
1
f0 =
2π (R3R2C1C2)
1
C = _{2πf0 R3R2} =
1
2π × 100 66700 × 3600
≈0.1μF
We obtain Q
R3R2
Q = _2R3
1
×
≈2.15
R3R2
Note item when using
(1) When turning on the power, the setting inside is unsettled. Before setting control data, it does a mute.
(2) To prevent the digital noise of the high frequency influence a terminal (SCL, SDA).
It can be protected by a signal line in the ground pattern or by the shielding cable.
(3) To prevent the noise in changing a mode, please set the mute ON.
Sample Application Circuit
No.8263-12/15