lc75374e Sanyo Semiconductor Corporation, lc75374e Datasheet - Page 12

• Manufacturer Part Number: lc75374e
• Description: Electronic Volume And Tone Control For Car Stereos
• Manufacturer: Sanyo Semiconductor Corporation

Sample external constant calculations for the super bass (T type) circuit when full boost is used
The external constants required when full boost is used with the super bass block (T type) are calculated as follows.
• Super bass (T type) equivalent circuit
• Calculation
(1) Center frequency
(2) Gain
(3) Q
Fader Volume Control Block Equivalent Circuit
At the point that data corresponding to –∞ is transferred to the 1dB –step main volume control block, S1 and S2 will go to the open state. S3 and S4 will go to
the on state at the same time.
f0 = ————————————
G = 20log
Q = —————
C C R1
2
2 C
1 + ———
R1 R2 C C
2 R2
1
R1
————————
R1 R2 C C
1
S2 and S3 will be on when FADER = 1.
S1 and S4 will be on when FADER = 0.
LC75374E
• Determine R2
• Determine C
• Determine Q
Sample calculation
Assume:
R1 = 64.5 kΩ, and
G = 20.65 dB, and
f0 = 72.7 Hz.
Determine R2 from formula (2).
Determine C from formula (1).
Determine Q from formula (3).
Here, Q will be 2.21.
R2 = ———————
C = ———————————————
R1 R2 (2
2 (10.78 – 1)
64.5
The right channel is identical.
1
f0) (2
3.3 (kΩ)
f0)
No. 5835-12/17
0.15 (µF)