Audio ICs
(13) DC control
There is internal impedance of 10kΩ at the VC (pin 23),
TC (pin 22), and BC (pin 21) pins, and internal imped-
ance of 200kΩ at the SC pin (pin 11). For this reason, it
is recommended that DC control of these pins be per-
formed by voltage delivered directly from the voltage
source. When using variable volume, take the imped-
ance into account in determining the settings.
Note: The voltage range for DC control is 0V to 3.8V. Be
sure not to apply greater than 3.8V to any pin.
(14) GND
S Connect the GND of the attached element, which is
shown in the circuit of the sample application, to the
analog GND.
S Connect the GND of the capacitor that is connected to
pin 17 to the digital GND.
S If several capacitors with good high-frequency charac-
FElectrical characteristic curves
BH3854AS / BH3854AFS
teristics are connected in parallel to the 17th-pin capac-
itor, the characteristics will be improved with respect to
static electricity noise. (Recommended: ceramic ca-
pacitors of 0.001µF to 0.1µF) If the wiring to the analog
GND and digital GND is long, make sure that no poten-
tial difference arises between the two GNDs.
(15) BH3854AS ! BH3854AFS: Differences
S The bass filter R2 constant changes from 100 kΩ ! 85
kΩ. Accordingly, bass filter f0 changes from 70Hz !
75Hz, which means bass filter Q changes from 1.47 !
1.36.
S The resistance at the treble filter’s TIN pin changes
from 20 kΩ ! 2 kΩ. Accordingly, the value for the at-
tached capacitor changes from 470pF ! 0.01µF,
which means that cutoff frequency (fC1) changes from
17kHz ! 8kHz.
FExternal dimensions (Units: mm)
647