CXA2022 Sony Corporation, CXA2022 Datasheet - Page 13

• Manufacturer Part Number: CXA2022
• Description: I2C Bus Sound Processor for TV
• Manufacturer: Sony Corporation

Description of Operation
• AGC circuit
• Surround circuit
Phase Shifter
Each of the phase shifters PS1, PS2 and PS3 consists of two stages of phase shifters (A, B). The transfer
function for a stage of phase shifter is expressed by the following equation.
R: Internal resistance ≈ 18kΩ, C: External capacitance
• TONE circuit
• BALANCE and VOLUME circuit
• DAC circuit
The AGC circuit is provided at the input. When AGC is set to ON, this circuit is 0dB for small signal input,
boosts for medium signal input, and achieves gain reduction for large signal input. The sound level
defference between input sources can be absorbed at this circuit.
The surround circuit provides three modes; MONO (Simulate Stereo), STEREO-1 and STEREO-2.
MONO mode
STEREO-1 mode
STEREO-2 mode
V
Provides tone controls for BASS and TREBLE. The external capacitance of C
can determine the characteristics. The number of steps is 32.
Provides controls for BALANCE and VOLUME. the number of steps is 64 each.
Provides controls for BASS, TREBLE, VOLUME and BALANCE. The internal impedance is approximately
20kΩ and the LPF capacitance is used externally.
O
L + R signals, passed through the mono filter and then through four stages of phase shifters (PS1A, PS1B,
PS2A, PS2B) and 9kHz LPF, are added to L and R channels at opposite phase to each other.
The surround effect can be changed by the MONO-EFFECT.
L-R signals, passed through two stages of phase shifters (PS1A, PS1B) and 9kHz LPF, are added to L and R
channels at opposite phase to each other. The surround effect can be changed by the SURR-EFFECT. In
addition, L + R signals passed through the middle frequency BPF (1kHz BPF) are added to L and R channels at
in-phase to each other to prevent "vocal missing" in the surround mode. The addition amount of middle
frequency can be changed by the VOCAL-MIX.
L-R signals, passed through two stages of phase shifters (PS1A, PS1B) and 9kHz LPF, are added to L and R
channels at opposite phase to each other. The surround effect can be changed by the SURR-EFFECT. In
addition, L + R signals passed through the middle frequency BPF (1kHz BPF) are added to R channel, and the
middle frequency signals passed further through two stages of phase shifters (PS3A, PS3B) are added to the L
channel. The addition amount of middle frequency (L and R) can be changed by the VOCAL-MIX.
=
1 – SCR
1 + SCR
Vin
– 13 –
L
for BASS and C
H
for TREBLE
CXA2022S