CXA1946AQ/AR
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Electronic Volume
Description
The CXA1946AQ/AR is a serial control electronic
volume IC designed for use in audio systems.
Features
• Loudness
• Volume control (0dB to –87dB in 1dB step, –∞dB)
• Balance
• Tone control (15 steps, 2 bands, –16dB to +16dB)
• Fader
(2dB-step to –20dB, –25dB, –35dB, –45dB, –60dB, –∞dB)
• Input selector (4 channels)
• Gain can be set for each input channel (common for channels 3 and 4)
• Serial data control (DATA, CLK, CE)
• Single 8V power supply
• Zero-cross detection circuit (with timer)
• Power-off mute
• Volume control and tone control input/output pins are separate.
48 pin QFP (Plastic)
48 pin LQFP (Plastic)
Absolute Maximum Ratings
• Supply voltage VCC 13 V
• Operating temperature Topr –40 to +85 °C
• Storage temperature Tstg –65 to +150 °C
• Allowable power dissipation PD QFP 350 mW (Ta = 85°C)
LQFP 180 mW (Ta = 85°C)
Operating Conditions
Supply voltage VCC 6 to 12 V
Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by
any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the
operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits.
– 1 –
E95602D7Y
Block Diagram and Pin Configuration
CXA1946AQ/AR
GAIN12
GAIN11
IN14
IN13
IN12
IN11
IN21
IN22
GAIN134
36
37
38
39
40
41
42
43
44
LDLC1
35
INPUT SW
ZCDET
LOUD
LDHC1
34
INAO1
33
8dB STEP
VOLUME
VRIN1
32
LATCH
SHI FT RE GISTER
VOUT1
31
1dB STEP
VOLUME
VCTBUFF
VCTBUFF
VCTBUFF
TIN1
30
TCHC1
29
L ATCH CONTROL
TCLC11
28
TONE
TCLC12
27
TCO1
26
100k
100k
FADER
FDIN1
25
FNTO1
24
REO1
23
CE
22
CLK
21
DGND
20
GND
19
CC
V
18
VCT
17
IN23
IN24
GAIN21
GAIN22
DATA
45
46
47
48
INPUT SW
VOLUME
3
LDHC2
8dB STEP
4
INAO2
5
VRIN2
LOUD
2
GAIN234
LDLC2
VCTBUFF
VCTBUFF
VCTBUFF
VOLUME
1dB STEP
6
VOUT2
TONE
7
8
TIN2
9
TCHC2
10
TCLC21
TCLC22
11
TCO2
FADER
121
16
TIMER
15
REO2
14
FNTO2
13
FDIN2
– 2 –
Pin Description
CXA1946AQ/AR
Pin
No.
1
36
2
35
Symbol
GAIN234
GAIN134
LDLC2
LDLC1
I/O resistance
Pin voltage
~
∞
–
VCT
6.18kΩ
VCT
36
35
Equivalent circuit
V
CC
1
GND
CC
V
2
Sets gain for IN3 and IN4.
Sets loudness low cut-off
frequency.
Description
3
34
4
33
LDHC2
LDHC1
INAO2
INAO1
8.92kΩ
VCT
—
VCT
34
33
GND
V
CC
3
Sets loudness high cut-off
frequency.
GND
V
CC
4
Input selector output
– 3 –
GND
CXA1946AQ/AR
Pin
No.
5
32
6
31
Symbol
VRIN2
VRIN1
VOUT2
VOUT1
I/O resistance
Pin voltage
9.5kΩ
VCT
—
VCT
31
32
6
Equivalent circuit
V
CC
5
Description
Volume input
GND
VCC
Volume output
7
30
8
29
TIN2
TIN1
TCHC2
TCHC1
19kΩ
VCT
5kΩ
VCT
30
GND
V
CC
7
GND
V
CC
8
29
Tone input
Sets tone high frequency.
– 4 –
GND
CXA1946AQ/AR
Pin
No.
17
18
19
20
21
Symbol
VCT
VCC
GND
DGND
CLK
I/O resistance
Pin voltage
—
VCT
VCC
GND
—
~
∞
–
—
21
Equivalent circuit
V
CC
GND
VCC
Description
Center electric potential
+ power supply
GND
Digital GND
Serial clock input
22
37
48
CE
GAIN12
GAIN22
~
∞
–
—
~
∞
–
VCT
37
48
22
GND
V
CC
GND
Latch enable input
Sets gain for IN2.
– 7 –
CXA1946AQ/AR
Pin
No.
38
47
39
40
41
42
43
44
45
46
Symbol
GAIN11
GAIN21
IN14
IN13
IN12
IN11
IN21
IN22
IN23
IN24
I/O resistance
Pin voltage
~
∞
–
50kΩ
VCT
47
39
40
41
42
38
Equivalent circuit
43
44
45
46
V
CC
GND
V
CC
GND
Description
Sets gain for IN1.
Signal input
– 8 –