LV1117N Datasheet, PDF (15/18 Pages) Sanyo Semicon Device – Surround Processor ICs for Electronic Volume Control

LV1117N/1117NV
Tone Circuit Constant Calculation Examples
Treble Band Circuit: The shelving characteristics can be obtained for the treble band.
The equivalent circuit and calculation formula during boost are indicated below.
• Calculation example 1
Specification Set frequency: f = 10000Hz
Gain during maximum boost: G_+18dB = 17.5dB
Let us use R1 = 6.51kΩ and R2 = 45.19kΩ
The above constants are inserted in the following formula
G = 20 × Log₁₀ 1+
R2
R1²+(1/ ω C)²
+
-
R2
R1
C
1
C=
2πf
R2
2
-R1²
10^G/20-1
=
1
≈2700 (pF)
2π24000
45190
2
- 6510²
7.50 - 1
Bass Band Circuit: The equivalent circuit and the formula for calculating the external RC with a mean frequency of
100Hz are shown below.
• Base band equivalent circuit diagram
• 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+
R3
2R3
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)
C=
1
=
2πf0 R3R2
1
2π × 100 66700 × 3600
≈0.1μF
We obtain Q
Q=
R3R2
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.
No.A1046-15/18