Description

The CXA1646Q/CXA1767Q is a serial control

electronic volume IC for car stereos.

Features

• Loudness

• Volume control

(1dB-step from 0dB to –87dB, –

∞

dB)

• Balance

• Tone control

(2dB-step 2 band from –14dB to +14dB)

• Fader

(2dB-step to –20dB, –25dB, –35dB, –45dB, –60dB, –

∞

dB)

• Input selector (4 channels)

• Serial data control (DATA, CLK, CE)

• Single 8V power supply

• Zero-cross detection circuit

Structure

Bipolar IC

Absolute Maximum Ratings (Ta = 25°C)

• Supply voltage

V

CC

13

V

• Operating temperature

Topr

–40 to +85

°C

• Storage temperature

Tstg

–65 to +150

°C

• Allowable power dissipation

P

D

350

mW (Ta = 85°C, 1646Q)

240

mW (Ta = 85°C, 1767Q)

Recommended Operating Condition

Supply voltage

V

CC

6 to 12

V

– 1 –

CXA1646Q/CXA1767Q

E92759D7Y

Electronic Volume

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.

CXA1646Q

48 pin QFP (Plastic)

CXA1767Q

40 pin QFP (Plastic)

– 2 –

CXA1646Q/CXA1767Q

Block Diagram and Pin Configuration

CXA1646Q

N

C

L

D

L

C

1

L

D

H

C

1

IN

A

O

1

V

R

IN

1

T

C

H

C

1

T

C

L

C

1

1

T

C

L

C

1

2

T

C

O

1

F

D

IN

1

F

N

T

O

1

N

C

N

C

L

D

L

C

2

L

D

H

C

2

IN

A

O

2

V

R

IN

2

T

C

H

C

2

T

C

L

C

2

1

T

C

L

C

2

2

T

C

O

2

F

D

IN

2

F

N

T

O

2

N

C

GAIN1

IN14

IN13

IN12

IN11

NC

NC

IN21

IN22

IN23

IN24

GAIN2

REO1

CE

TEST

CLK

GND

NC

NC

V

CC

VCT

DATA

INIT

REO2

VCTBUFF

VCTBUFF

SHIFT REGISTER

LATCH

LATCH CONTROL

VOLUME

8dB STEP

VOLUME

1dB STEP

TONE

IN

P

U

T

S

W

FADER

VCTBUFF

VCTBUFF

LOUD

ZCDET

IN

P

U

T

S

W

LOUD

8dB STEP

VOLUME

1dB STEP

VOLUME

TONE

FADER

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

36

35

34

31

32

33

40

39

38

37

41

42

43

44

45

46

47

48

2

3

4

5

6

7

8

9

10

11

12

1

– 3 –

CXA1646Q/CXA1767Q

CXA1767Q

L

D

L

C

1

L

D

H

C

1

IN

A

O

1

V

R

IN

1

T

C

H

C

1

T

C

L

C

1

1

T

C

L

C

1

2

T

C

O

1

F

D

IN

1

F

N

T

O

1

L

D

L

C

2

L

D

H

C

2

IN

A

O

2

V

R

IN

2

T

C

H

C

2

T

C

L

C

2

1

T

C

L

C

2

2

T

C

O

2

F

D

IN

2

F

N

T

O

2

GAIN1

IN14

IN13

IN12

IN11

IN21

IN22

IN23

IN24

GAIN2

REO1

CE

TEST

CLK

GND

V

CC

VCT

DATA

INIT

REO2

VCTBUFF

VCTBUFF

SHIFT REGISTER

LATCH

LATCH CONTROL

VOLUME

8dB STEP

VOLUME

1dB STEP

TONE

IN

P

U

T

S

W

FADER

VCTBUFF

VCTBUFF

LOUD

ZCDET

IN

P

U

T

S

W

LOUD

8dB STEP

VOLUME

1dB STEP

VOLUME

TONE

FADER

21

22

23

24

25

26

27

28

29

30

36

35

34

31

32

33

40

39

38

37

13

14

15

16

17

18

19

20

11

12

2

3

4

5

6

7

8

9

10

1

– 4 –

CXA1646Q/CXA1767Q

Pin Description (Pin No. in the parenthesis is for CXA1767Q.)

Pin No.

2 (1)

35 (30)

LDLC2
LDLC1

5.28k

Ω

VCT

Symbol

Sets loudness low
cut-off frequency.

I/O resistance

Pin voltage

Equivalent circuit

Description

Vcc

GND

3 (2)

34 (29)

LDHC2
LDHC1

7.97k

Ω

VCT

Sets loudness high
cut-off frequency.

Vcc

GND

4 (3)

33 (28)

INAO2
INAO1

—

VCT

Input selector output

Vcc

GND

5 (4)

32 (27)

VRIN2
VRIN1

50k

Ω

VCT

Volume input

Vcc

GND

– 5 –

CXA1646Q/CXA1767Q

Pin No.

6 (5)

31 (26)

TCHC2
TCHC1

5k

Ω

VCT

Symbol

Sets tone high
frequency.

I/O resistance

Pin voltage

Equivalent circuit

Description

Vcc

GND

7 (6)

30 (25)

TCLC21
TCLC11

8k

Ω

VCT

Sets tone low
frequency.

Vcc

GND

8 (7)

29 (24)

TCLC22
TCLC12

8k

Ω

VCT

Sets tone low
frequency.

Vcc

GND

9 (8)

28 (23)

TCO2
TCO1

—

VCT

Tone control output

Vcc

GND

– 6 –

CXA1646Q/CXA1767Q

Pin No.

10 (9)

27 (22)

FDIN2
FDIN1

24k

Ω

VCT

Symbol

Fader input

I/O resistance

Pin voltage

Equivalent circuit

Description

Vcc

GND

11 (10)
26 (21)

FNTO2
FNTO1

—

VCT

Front output

Vcc

GND

13 (11)
24 (20)

REO2
REO1

—

VCT

Rear output

Vcc

GND

14 (12)

INIT

—
—

System reset

Vcc

GND

– 7 –

CXA1646Q/CXA1767Q

Pin No.

15 (13)

DATA

∞

—

Symbol

Serial data input

16 (14)

VCT

—

VCT

1
2

V

CC

17 (15)

V

CC

V

CC

+power supply

20 (16)

GND

GND

GND

I/O resistance

Pin voltage

Equivalent circuit

Description

Vcc

GND

21 (17)

CLK

Serial clock

Vcc

GND

23 (19)

CE

Latch enable

Vcc

GND

22 (18)

TEST

—
—

Test. Leave open.

∞

—

∞

—

~

–

~

–

~

–

– 8 –

CXA1646Q/CXA1767Q

Pin No.

37 (31)
48 (40)

GAIN1
GAIN2

10k

Ω

VCT

Symbol

Sets input amplifier
gain to 6dB by
connecting to VCT.
0dB at open.

I/O resistance

Pin voltage

Equivalent circuit

Description

Vcc

GND

10k

Ω

10k

Ω

38 (32)
39 (33)
40 (34)
41 (35)
44 (36)
45 (37)
46 (38)
47 (39)

Mode

Set value

INPUT
VRC1
VRF1
VRC2
VRF2
LOUD
TONE BASS
TONE TREBLE
FADER

1
–

∞

–7dB
–

∞

–7dB
OFF
0dB
0dB
0dB, REAR

IN14
IN13
IN12
IN11
IN21
IN22
IN23
IN24

50k

Ω

VCT

Signal input

Vcc

GND

Reset

Reset is performed by lowering the INIT pin below 1V when CLK is High. Reset is disabled when CLK is Low.

The following table shows the reset status.

– 9 –

CXA1646Q/CXA1767Q

Data Format

(a) Data allocation

FAST BIT

MSB

LAST BIT

LSB

D1
D2

D3
D4

D5

D6
D7
D8
D9

D10
D11
D12

D13
D14
D15
D16

D17
D18
D19

D20
D21
D22
D23

D24
D25
D26
D27

D28
D29
D30
D31

D32

NOP

ISW

LOUD

VRC1

VRF1

VRC2

VRF2

TONE BASS

TONE TREBLE

FADER

FADER SELECT

– 10 –

CXA1646Q/CXA1767Q

(b) Set table

• NOP

Set value

—

0

D1

0

D2

• ISW

Set value

IN14/IN24
IN13/IN23
IN12/IN22
IN11/IN21

1
1
0
0

D1

1
0
1
0

D2

• LOUD

Set value

ON
OFF

1
0

D5

• VRC1/VRC2

Set value

O
–8
–16
–24
–32
–40
–48
–56
–64
–72
–80
–

∞

–

∞

1
1
1
1
1
1
1
1
0
0
0
0
0

D6/D13

1
1
1
1
0
0
0
0
1
1
1
1
0

D7/D14

1
1
0
0
1
1
0
0
1
1
0
0
0

D8/D15

1
0
1
0
1
0
1
0
1
0
1
0
0

D9/D16

• VRF1/VRF2

Set value

O
–1
–2
–3
–4
–5
–6
–7

1
1
1
1
0
0
0
0

D10/D17

1
1
0
0
1
1
0
0

D11/D18

1
0
1
0
1
0
1
0

D12/D19

– 11 –

CXA1646Q/CXA1767Q

• TONE BASS/TREBLE

Set value

14
12
10
8
6
4
2
0

1
1
1
1
0
0
0
0

D20/D24

1
1
0
0
1
1
0
0

D21/D25

1
0
1
0
1
0
1
0

D22/D26

• BOOST/CUT

Set value

BOOST
CUT

1
0

D23/D27

• FADER SELECT

Set value

Attenuation of front signal
Attenuation of rear signal

1
0

D32

• FADER

Set value

–

∞

–60
–45
–35
–25
–20
–18
–16
–14
–12
–10
–8
–6
–4
–2
0

1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0

D28

1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0

D29

1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0

D30

1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0

D31

– 12 –

CXA1646Q/CXA1767Q

• DATA TIMING

min 0.5µs

max 1MHz

min 0.5µs

CE

DATA

CLK

CE

min 4µs

D1

D2

D3

D31

D32

– 13 –

CXA1646Q/CXA1767Q

Electrical Characteristics

(V

CC

= 8V, Ta = 25°C unless otherwise specified)

Circuit current

Total harmonic distortion factor

Output noise voltage

Maximum output voltage

Separation

Maximum attenuation factor

Loudness

Bass max. boost gain

Bass max. cut gain

Treble max. boost gain

Treble max. cut gain

Gain switching

Input voltage

Input voltage range

I

CC

THD

Vn

Vom

CS

ATTm

Glb

Glh

Gbb

Gbc

Gtb

Gtc

Gh

Vsh

Vsl

Vin

No signal

1kHz, 5dBm

Shortcircuit at input, Aweight

1kHz

1kHz

100Hz, VRC = –16dB

10kHz, VRC = –16dB

GAIN = VCT

DATA, INIT
CLK, CE

IN11 to 14
IN21 to 24
VRIN1, 2
FDIN1, 2

—

—

—

8

72

85

7

7

12

12

12

12

5

3

0

1

17

0.005

7

—

90

90

8

8

14

14

14

14

6

—

—

—

21

0.01

10

—

—

—

9

9

16

16

16

16

7

6

1.5

V

CC

– 1

mA

%

µVrms

dBm

dB

dB

dB

dB

dB

dB

dB

dB

dB

V

V

V

LOW

HIGH

H

L

Item

Symbol

Conditions

Min.

Typ.

Max.

Unit

– 14 –

CXA1646Q/CXA1767Q

Electrical Characteristic Test Circuit

R

E

O

1

C

E

T

E

S

T

C

L

K

G

N

D

N

C

N

C

V

C

C

V

C

T

D

A

T

A

IN

IT

R

E

O

2

IN

AO

1

NC

FN

TO

1

FD

IN

1

TC

O1

TC

LC

12

TC

LC

11

TC

HC

1

VR

IN

1

LD

HC

1

LD

LC

1

NC

NC

FN

TO

2

FD

IN

2

TC

O2

TC

LC

22

TC

LC

21

TC

HC

2

VR

IN

2

IN

AO

2

LD

HC

2

LD

LC

2

NC

G

A

IN

1

IN

1

4

IN

1

3

IN

1

2

IN

1

1

N

C

N

C

IN

2

1

IN

2

2

IN

2

3

IN

2

4

G

A

IN

2

C1

2

0.0

47

µ

A

C

V

1

4

C

1

4

1

0

µ

C

2

1

0

.0

4

7

µ

V

4

R

7

1

k

A

C

V

5

S

1

O

P

A

M

P

C

1

1

0

.0

4

7

µ

C

1

3

C

1

5

0

.2

2

µ

C

1

7

1

0

µ

R

1

1

1

0

k

2

5

2

6

2

7

2

8

2

9

3

0

3

6

3

5

3

4

3

1

3

2

3

3

S

2

S

1

4

S

1

3

S

1

2

A

C

V

1

3

A

C

V

1

2

A

C

V

1

1

S

1

1

A

C

V

2

1

S

2

1

S

2

2

S

2

3

A

C

V

2

2

A

C

V

2

3

A

C

V

2

4

S

2

4

S

1

5

S

2

5

4

0

3

9

3

8

3

7

4

1

4

2

4

3

4

4

4

5

4

6

4

7

4

8

C

2

2

0

.0

0

4

7

µ

C

2

3

C

2

4

C

2

5

0

.2

2

µ

C

2

7

R

2

1

1

0

k

1

2

2

3

4

5

6

7

8

9

1

0

1

1

1

R

1

2

R

V

1

R

3

1

k

R

5

1

k

R

1

C

1

2

2

0

p

V

5

R

6

1

k

V

2

O

P

A

M

P

C

2

1

0

µ

V

1

C

1

0

.0

0

1

µ

R

2

2

1

0

k

1

3

1

4

1

5

1

6

1

7

1

8

1

9

2

0

2

1

2

2

2

3

2

4

5

V

0

V

5

V

0

V

5

V

0

V

C

E

C

L

K

D

A

T

A

C

X

A

1

6

4

6

Q

– 15 –

CXA1646Q/CXA1767Q

Application Circuit

R

E

O

1

C

E

T

E

S

T

C

L

K

G

N

D

N

C

N

C

V

C

C

V

C

T

D

A

T

A

IN

IT

R

E

O

2

IN

AO

1

NC

FN

TO

1

FD

IN

1

TC

O1

TC

LC

12

TC

LC

11

TC

HC

1

VR

IN

1

LD

HC

1

LD

LC

1

NC

NC

FN

TO

2

FD

IN

2

TC

O2

TC

LC

22

TC

LC

21

TC

HC

2

VR

IN

2

IN

AO

2

LD

HC

2

LD

LC

2

NC

G

A

IN

1

IN

1

4

IN

1

3

IN

1

2

IN

1

1

N

C

N

C

IN

2

1

IN

2

2

IN

2

3

IN

2

4

G

A

IN

2

C1

2

0.0

04

7µ

C

1

5

1

0

µ

C

1

7

1

0

µ

C

2

3

1

0

µ

C

2

5

1

0

µ

C

2

6

0

.2

2

µ

C

2

7

1

0

µ

1

2

2

3

4

5

6

7

8

9

1

0

1

1

1

C

2

1

0

µ

C

X

A

1

6

4

6

Q

C1

4

0.0

06

8µ

C1

6

0.2

2µ

C

1

3

1

0

µ

C

1

1

0

.0

4

7

µ

O

N

6

D

B

O

F

F

0

D

B

C

2

4

0

.0

0

6

8

µ

C

2

2

0

.0

0

4

7

µ

C

2

1

0

.0

4

7

µ

O

N

6

D

B

O

F

F

0

D

B

C

3

3

3

µ

C

1

0

.0

0

1

µ

1

3

1

4

1

5

1

6

1

7

1

8

1

9

2

0

2

1

2

2

2

3

2

4

4

0

3

9

3

8

3

7

4

1

4

2

4

3

4

4

4

5

4

6

4

7

4

8

2

5

2

6

2

7

2

8

2

9

3

0

3

6

3

5

3

4

3

1

3

2

3

3

Application circuits shown are typical examples illustrating the operation of the devices. Sony cannot assume responsibility fo

r

any problems arising out of the use of these circuits or for any infringement of third party patent and other right due to same

.

– 16 –

CXA1646Q/CXA1767Q

+14dB

+12dB

+10dB

+8dB

+6dB

+4dB

+2dB

0dB

–2dB

–4dB

–6dB

–8dB

–10dB

–12dB

–14dB

CXA1646Q/CXA1767Q Tone control characteristics

R

e

s

p

o

n

s

e

[

d

B

]

Frequency [Hz]

10

100k

10k

1k

100

–10

10

0

CXA1646Q/CXA1767Q Loud characteristics

R

e

s

p

o

n

s

e

[

d

B

]

Frequency [Hz]

10

10k

1k

100

–20

0

10

VRC = –24dB

VRC = –16dB

VRC = –8dB

VRC = 0dB

– 17 –

CXA1646Q/CXA1767Q

Setting Constants

• LOUD

The loudness function achieves the necessary frequency characteristics by passing through filter shown below.

The resistor is built in the IC so that f

L

and f

H

are set by selecting C

LDLC

and C

LDHC

.

I/f

L

= 2

π

C

LDLC

R

1

I/f

H

= 2

π

C

LDHC

R

2

C

LDLC

R1

5.28k

R2

7.97k

28k

13.2k

AGND

AGND

C

LDHC

f

H

f

L

– 18 –

CXA1646Q/CXA1767Q

• TONE CONTROL

The tone control function achieves the necessary frequency characteristics by passing through LPF and HPF

shown below.

The resistor is built in the IC so that f

L

and f

H

are set by selecting C

TLC12

and C

TCHC

.

I/f

L

= 2

π

C

TCLC12

(R

3

//R

4

)

I/f

H

= 2

π

C

TCHC

R

3

LPF

HPF

R4

8k

AGND

8k

8k

AGND

AGND

R3

8k

C

TCLC12

10k

f

H

f

L

10k

10k

AGND

AGND

C

TCHC

R3

5k

10k

– 19 –

CXA1646Q/CXA1767Q

• VCT pin

The internal circuit of VCT pin has the following structure.

Insert a buffer when using it as a reference voltage for an external circuit.

GND

V

CC

45k

45k

VCT

– 20 –

CXA1646Q/CXA1767Q

Package Outline

Unit: mm

CXA1646Q

SONY CODE

EIAJ CODE

JEDEC CODE

M

PACKAGE STRUCTURE

PACKAGE MATERIAL

LEAD TREATMENT

LEAD MATERIAL

PACKAGE WEIGHT

EPOXY RESIN

SOLDER / PALLADIUM

PLATING

COPPER / 42 ALLOY

48PIN QFP (PLASTIC)

15.3 ± 0.4

12.0 – 0.1

+ 0.4

0.8

0.3 – 0.1

+ 0.15

± 0.12

13

24

25

36

37

48

1

12

2.2 – 0.15

+ 0.35

0

.9

±

0

.2

0.1 – 0.1

+ 0.2

1

3

.5

0.15

0.15 – 0.05

+ 0.1

QFP-48P-L04

∗

QFP048-P-1212-B

0.7g

NOTE : PALLADIUM PLATING

This product uses S-PdPPF (Sony Spec.-Palladium Pre-Plated Lead Frame).

– 21 –

CXA1646Q/CXA1767Q

CXA1767Q

SONY CODE

EIAJ CODE

JEDEC CODE

PACKAGE MATERIAL

LEAD TREATMENT

LEAD MATERIAL

PACKAGE WEIGHT

EPOXY RESIN

SOLDER / PALLADIUM

COPPER / 42 ALLOY

PACKAGE STRUCTURE

PLATING

0.2g

QFP-40P-L01

∗

QFP040-P-0707

40PIN QFP (PLASTIC)

9.0 ± 0.4

+ 0.4

0.3 – 0.1

0.65

1

10

11

20

21

30

31

40

1.5 – 0.15

+ 0.35

0.127 – 0.05

+ 0.1

(8

.0

)

A

A

DETAIL

0.1 – 0.1

+ 0.15

+ 0.15

7.0 – 0.1

0

.5

±

0

.2

0.1

M

± 0.12