CXA1878Q
8. Recording volume balance circuit
The CXA1878Q contains a circuit which controls the balance between channels 1 and 2 of the recording
volume.
Therefore, the balance between channels 1 and 2 can be controlled by applying the voltage between DVCC
and DGND to the REC BAL pin (Pin 29).
(Signals which are not attenuated by the balance circuit are output from both channels when this control pin is
open or when a voltage of DVCC/2 is applied.)
REC VOL Control Voltage
Pin voltage (V)
Pin No.
Symbol
Remarks
0.0
0.5
2.0
4.5
5.0
9.0
Decrease <<<< Increase
VOLOUT1 and 2 attenuation (dB)
BALANCE = 2.5V, f = 1kHz
28
REC VOL
Less
than –96
–96
0.0
—
BALANC control voltage
Pin voltage (V)
2.5
Pin No.
Symbol
Remarks
0.0
0.0
0.5
4.5
5.0
Increase >>>> Decrease
0.0 0.0 –93
Decrease <<<< Increase
–93 0.0 0.0
VOLOUT2 attenuation (dB)
REC VOL = 5V, f = 1kHz
Less
than –93
29
REC BAL
VOLOUT1 attenuation (dB)
REC VOL = 5V, f = 1kHz
Less
than –93
0.0
9. Bias OSC power supply control circuit
The CXA1878Q contains a switch circuit that selects the supply voltage for the bias oscillator.
The supply voltage can be controlled with the B EQ pin (Pin 24). The maximum output current is 2mA.
– 28 –
SONY [ SONY CORPORATION ]
