LC78855 Ver la hoja de datos (PDF) - SANYO -> Panasonic
Número de pieza
componentes Descripción
Fabricante
LC78855 Datasheet PDF : 9 Pages
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LC78855KM
— Attenuation data settings (serial input mode)
When D7 is low: Bits D0 to D6 are input as attenuation data.
When D7 is high: Bits D0 to D6 are not input and no attenuation data transformation is performed.
The table below shows the relationship between the attenuation data and the output.
Attenuation data
7F (HEX)
7E (HEX)
·
·
·
01 (HEX)
00 (HEX)
Audio output (dB)
0
–0.137
·
·
·
–42.144
–∞
The attenuation for the values 01 to 7E (hexadecimal) is given by the following formula.
Attenuation = 20 · log(input data/128) (dB)
The digital attenuation interval shifts with a slope of 1024/Fs (s) from 0 to –∞ (dB). If new data is input during
a transition, the value begins to change towards the new value at that time.
— Soft muting switch (parallel input mode)
Soft muting can be applied by switching the value input to pin CNT3.
When CNT3 is high, soft muting will be applied.
Soft muting shifts the amplitude from 0 to –∞ (dB) at 1024/Fs (s).
3. Initialization
The LC78855KM requires initialization when power is first applied and when the system clock is switched. A reset
can be effected by setting the RESETB pin to the low level. The time that low level is held must be at least the time
necessary for the power supply voltage to stabilize, the XIN, BCLK and LRCK signals to be applied and for LRCK
to complete at least one cycle as shown in the figure below.
When RESETB is low, all digital outputs and the internal noise shaper go to zero and the D/A converter outputs an
analog zero.
No. 4999-6/9
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