CXA2021S
<Description of Operations>
• AGC circuit
The AGC circuit is incorporated in the input block. When AGC is turned ON, gain is 0dB for small signal
input, boosted for medium signal input and reduced for large signal input. The AGC circuit can absorb
volume differences between input sources.
• Surround circuit
L-R signals passing through the phase shifter are added to L channel and R channel each in the opposite
phase. The transfer function of the phase shifter is obtained by the following equation:
1 – SCR
VO =
Vin
1 + SCR
where R is internal resistance ≈ 18kΩ and C is external capacitance.
• TONE circuit
BASS and TREBLE tone control. BASS control characteristic can be determined by external capacitance
connected to CL, and TREBLE control characteristic by external capacitance connected to CH. Tone control
can be performed in 32 steps.
• BALANCE and VOLUME circuits
Controls BALANCE and VOLUME in 64 steps each.
• DAC
DAC circuit for controlling BASS, TREBLE, VOLUME and BALANCE. Internal impedance is approximately
20kΩ. Connect external capacitance for LPF.
– 13 –