BH3868BFS Datasheet, PDF (25/28 Pages) Rohm – Audio sound processor with BBE

Audio ICs
BH3868BFS
3. Step switching noise
In an example of application circuit, an example of constant is set on VC1, VC2, TC and BC terminals. This constant
varies depending on signal level setting, actual wiring pattern, etc. Specify each constant under careful study and
examination. The internal equivalent circuit is shown below. (A primary integration circuit is set for gradual variation.)
R _{Every terminal}
+
C
−
(External)
VC1, VC2, TC, BC
R value (kΩ)
30
4. Level setting of volume and tone
Attenuation to control serial data is stated as a reference value in our specifications.
An internal D/A converter is configured by the R-2R method and, therefore, there is any data also in an area in which
some data are not consecutive. Use is for fine adjustment.
However, the volume must be within 8 bits (256 steps) and the tone must be 7 bits (64+1 steps).
5. I²C BUS control
High-frequency digital signal is inputted into the SCL terminal and SDA terminal. Therefore, However, wire not to
interfere any analog signal system line.
6. Power-on Reset
This IC contains a circuit for initialization when the power supply turns on. Every channel volume has been set to
become −∞ when the power supply turns on. When the power supply is turned ON once and OFF and then ON
again immediately, the said description may not be achieved if any load remains in a capacitor. In this case, apply
muting until a command of I²C BUS has been sent.
7. Capacitor of VREF (8pin)
100µF is recommended as the capacity of power supply filter attached to VREF. If this capacity is decreased, the
maximum attenuation of volume is deteriorated and the cross-talk also tends to become worse. This IC contains
a precharge circuit and discharge circuit for capacitor attached to VREF.
!BBE process
The BBE sound processor considers a loudspeaker and amplifier as total audio system, reproduces accurately “Rise of
Sound” which characterizes the sound, by an appropriate signal processing at a stage before amplifier input, and makes
the playback sound an original one as naturally as possible.
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