LC75010W View Datasheet(PDF) - SANYO -> Panasonic
Part Name
Description
Manufacturer
LC75010W Datasheet PDF : 12 Pages
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LC75010W
Notes on Filter Coefficient Settings (precision of calculations)
The IIR filter calculations are performed using 24-bit coefficients, 24-bit delay functions, 24 × 24 = 48-bit
multiplications, and 48 + 48 = 48-bit additions.
For certain values of the filter coefficients, the precision can become inadequate during the process of the filter
calculation. Such errors can result in switching noise occurring when changing between different steps in the volume
control.
*: This problem can occur when setting the second-order IIR with filter coefficients having low characteristic
frequencies (for example, the cutoff frequency or the center frequency). For example, switching noise will occur if
the coefficients for a high-pass filter with a cutoff frequency of 25 Hz and a Q of 0.7 are set with FixEQ.)
The following workaround can be effective if switching noise occurs due to second-order IIR filter coefficient
settings.
• Increase the characteristic frequency without changing the second-order characteristics, for example, increase the
cutoff frequency from 25 Hz to 100 Hz.
• Use the second-order characteristics as the first-order characteristics and define the coefficients for first-order
characteristics.
• Serial Input Data Format Examples
Example 1: Data format for the volume function
CCB Address
volume function data
control data
(8 bits)
(24 bits)
(24 bits)
bit 0
78
31 32
55
LSB(B0, B1, … , A3, DI1, DI2, … … DI23, DI24, C1, C2, … … , C23, C24)MSB
Example 2: Data format for 24-bit coefficient data (Total: 200 bits maximum)
CCB Address Coefficient data0 Coefficient data1
(8 bits)
(24 bits)
(24 bits)
bit 0 7 8
31 32
LSB(B0, B1,… , A3, DI1, DI2, …
…
55 56
…
Coefficient address
control data
(24 bits)
(16 bits)
(8 bits)
150151
175176
191192 199
…
DI168, C1, C2, … … C23, C24)MSB
• Serial Output Data Format Example
Example 1: CCB status register format (Total: 64 bits)
CCB Address CCB status
Monitor data1
(8 bits) (8 bits)
(24 bits)
bit0
78
15 16
LSB(B0, B1, …, A3, S1, S2, S8, DO1, DO2, …
39 40
…
…
Monitor data2
(24 bits)
63
…
, DO47, DO48)MSB
No. N7349-10/12
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