cxa1878q Sony Electronics, cxa1878q Datasheet - Page 28

• Manufacturer Part Number: cxa1878q
• Description: Dolby B-c Type Noise Reduction System With Recording/playback Equalizer Amplifier
• Manufacturer: Sony Electronics

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 DV
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 DV
REC VOL Control Voltage
BALANC control voltage
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.
Pin No.
Pin No.
28
29
REC VOL
REC BAL
Symbol
Symbol
Less
than –96
Less
than –93
0.0
0.0
0.0
CC
/2 is applied.)
Decrease <<<< Increase
Increase >>>> Decrease
Decrease <<<< Increase
–96
–93
0.5
0.5
0.0
Pin voltage (V)
Pin voltage (V)
2.0
0.0
2.5
0.0
0.0
– 28 –
–93
4.5
4.5
0.0
—
Less
than –93
5.0
9.0
5.0
0.0
VOLOUT1 and 2 attenuation (dB)
BALANCE = 2.5V, f = 1kHz
VOLOUT2 attenuation (dB)
REC VOL = 5V, f = 1kHz
VOLOUT1 attenuation (dB)
REC VOL = 5V, f = 1kHz
Remarks
Remarks
CXA1878Q
CC