cxa1946aq Sony Electronics, cxa1946aq Datasheet - Page 18

• Manufacturer Part Number: cxa1946aq
• Description: Electronic Volume
• Manufacturer: Sony Electronics

2. Volume
3. Loudness
The volume circuit consists of two sections, an 8dB/step section and a 1dB/step section, as shown in Fig. 3.
This circuit also serves as a balance control because the volume for channel 1 and channel 2 can be set
independently.
To mute the output signal, send – dB data.
The input impedance is 9.5k (typ.) for VRIN1 and VRIN2.
The output impedance for VOUT1 and VOUT2 is low impedance (roughly 0 ). The volume step width and
gain are not affected by the load impedance.
The configuration of the loudness circuit is shown in Fig. 3. C
and the loudness frequency characteristics are determined by these constants. The relationships between
C
The loudness characteristics are not affected by the load impedance of VOUT1 and VOUT2.
Loudness is turned on and off by serial data bit D5.
LDHCX
0.0022µ
C
LDHCX
1/f
1/f
/C
L
H
C
0.047µ
= 2 C
LDLCX
= 2 C
LDLCX
and the frequency characteristics are as follows:
LDLCX
LDHCX
LDHCX
LDLCX
VRINX (input impedance 9.5k )
8.92k
R
R2
R
INX4
INX3
INX2
INX1
1
25.7k
2
20k
GAINX2
GAINX1
4.98k
Loudness
50k
50k
50k
50k
6.18k
R1
20k
LOUD
Fig. 3. Volume and Loudness
VCT
OFF
ON
Fig. 2. Input Selector (2)
GAINX34
– 18 –
Total 40k
LDHCX
and C
Volume
Loudness frequency
characteristics
INAOX
f
L
LDLCX
are connected externally,
f
H
VOUTX
CXA1946AQ/AR