Sony CXA2020S, CXA2020M Datasheet

Description

The CXA2020M/S, is a bipolar IC designed as
EIAJ TV sound multiplexing decoder, provides
various functions including sound multiplexing
demodulation, broadcast mode identification
(stereo/bilingual discrimination display), mode
display, and muting.

Features

• Adjustment free of filter.

• High frequency stereo separation improved.

• An internal active filter greatly reduces the external

parts.

• Use of the countdown method for broadcast mode

identification eliminates the necessity of adjusting

the identification system (Cue oscillator).

• Output level: 520mVrms (1kHz, monaural, 100%).

• Internal filter eliminates interference from digital

facsimile signals.

• The discrimination time needed to shift from

multiplexing sound to monaural sound is reduced.

• Forced monaural mode can be set to operate only

for stereo broadcasts or for stereo/bilingual

broadcasts.

Applications

• Color TVs

• Hi-Fi VCRs

Structure

Bipolar silicon monolithic IC

Pin Configuration

Absolute Maximum Ratings (Ta = 25°C)

[ ( ) is the pin No. for the CXA2020S.]

• Supply voltage VCC 10 V

• Input signal (Pin 6) Vis 0.6 Vp-p

• Control voltage

(Pins 5, 12, 13, 14) Vic VCC V

• Operating temperature Topr –20 to +75 °C

• Storage temperature Tstg –65 to +150 °C

• Allowable power dissipation

PD (A2020M) 1000 mW

(A2020S) 900 mW

• LED drive current ILED 10 mA
Operating Supply Voltage Range 8.5 to 9.5 V

– 1 –

CXA2020M/S

E94Y28-ST

EIAJ Sound Multiplexing Decoder

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.

CXA2020S

22 pin SDIP (Plastic)

CXA2020M

28 pin SOP (Plastic)

2
3
4
5
6
7
8
9

10

11

12

13

14

15

16

17

18

19

20

21

22

1

GND

NC

REFL

Vcc

MO MODE

MPX IN

NC

CUBI

LEDST

LEDSU

LEDM

SUBI

SC OUT
SC IN

MC OUT
MC IN

L OUT
R OUT
M OUT

FOMO
MUTE

MODE

CXA2020S

2
3
4
5
6
7
8
9

10

11
12
13
14

15

16

17

18

19

20

21

22

1

GND

NC

REFL

Vcc

MO MODE

MPX IN

NC

CUBI

LEDST

LEDSU

LEDM

SUBI

SC OUT
SC IN

MC OUT
MC IN
L OUT

R OUT
M OUT

FOMO
MUTE
MODE

CXA2020M

NC

23

24

25

26

27

28

NC

NC

NC

NC

NC

CXA2020M CXA2020S

– 2 –

CXA2020M/S

Block Diagram

CXA2020M

CXA2020S

GND

NC

REFL

Vcc

MO MODE

MPX IN

NC

CUBI

LEDST

LEDSUB

LEDMAIN

SUBI

SC OUT

SC IN

MC OUT

MC IN

L OUT

R OUT

M OUT

FOMO

MUTE

MODE

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

1

IBIAS

VOLTAGE
REGULATOR

BIAS
CURRENT

BUFFER

BIAS
VOLTAGE

MPX SIGNAL

IN AMP

4.5fH

TRAP

SUB
BPF

SUB
DET

CUE
BPF

AM
DEMOD

952Hz
BPF

COMP

LED
DRIVE

3.5f

H

VCO

CUE
CARRIER

952Hz
CLOCK

3.5f

H

CLOCK

IIL LOGIC & CONT

MAIN

OUT

OUTPUT AMP

& OUTPUT SW

MATRIX

SUB

MAIN

L R

TEST

MAINDEEM

SUBDEEM

FM
DEMOD

23

24

25

26

27

28

NC

NC

NC

NC

NC

NC

GND

NC

REFL

Vcc

MO MODE

MPX IN

NC

CUBI

LEDST

LEDSUB

LEDMAIN

SUBI

SC OUT

SC IN

MC OUT

MC IN

L OUT

R OUT

M OUT

FOMO

MUTE

MODE

2

3

4

5

6

7

8

9

10

11

12

13

1415

16

17

18

19

20

21

22

1

IBIAS

VOLTAGE
REGULATOR

BIAS
CURRENT

BUFFER

BIAS
VOLTAGE

MPX SIGNAL

IN AMP

4.5fH

TRAP

SUB

BPF

SUB
DET

CUE
BPF

AM
DEMOD

952Hz
BPF

COMP

LED
DRIVE

3.5f

H

VCO

CUE
CARRIER

952Hz
CLOCK

3.5f

H

CLOCK

IIL LOGIC & CONT

MAIN

OUT

OUTPUT AMP

& OUTPUT SW

MATRIX

SUB

MAIN

L R

TEST

MAINDEEM

SUBDEEM

FM
DEMOD

– 3 –

CXA2020M/S

Pin Description (Ta = 25°C, VCC = 9V) The pin numbers in parentheses are for the CXA2020S.

PIn No.

SDIP

SOP

Symbol

11 GND 0 GND.

2
7

2
5

8
10
14
15
24
27

NC

—

Keep these pins open.
(They are not
connected to the chip.)

33 REFL 1.2V

The noise elimination
filter connection of
internal reference
voltage.

67 MPXIN 4.1V

Sound multiplexing
signal input.
Typical input level

= 70mVrms

(monaural, 100%)

89 CUBI 4.1V

Bias capacitor
connection of Cue
pulse generator.

56 MO MODE —

Forced monaural mode
selection.
When Low or open, the
forced monaural mode
operates for stereo
broadcasts only;
if High, the forced
monaural mode
operates for both
stereo and bilingual
broadcasts.

44 VCC — Power supply.

Pin

voltage

Equivalent circuit

Description

Vcc

147

GND

3

3.3k
20k 20k

24k

GND

(5)

10.5k

6

50k

70k

Vcc

147

80µ

GND

138k

(6)

25k

30k

4.2V

7

Vcc

147

(8)

1k

40k

40k

40k

Vcc

11k

2k

4.2V

9

—

– 4 –

CXA2020M/S

Pin No.

SDIP

SOP

Symbol

911 LEDST

1113 LEDM

1216 MODE

1012 LEDSU

—

Mode indicator LED
connection.

Pin 11 (9): stereo
Pin 12 (10): sub
Pin 13 (11): main

—

DC voltage-based
output mode switch for
bilingual broadcasts.

1317 MUTE

—

Output muting.
When High, only DC is
output from Pins 19, 20
and 21 (15, 16 and 17).

1418 FOMO

—

Forced monaural.
When High, forced
monaural (main sound)
mode is selected and
the LED turns off.

1519 MOUT

4.1V

Main signal output.
Always outputs the main
signal component,
regardless of the
broadcast mode.

Pin

voltage

Equivalent circuit

Description

GND

(9)

(10)

(11)

11

12

13

64k

16k

10.5k

64k

16k

10.5k
64k

16k

10.5k

(12)

20k

10.5k

40k

16k

Vcc

20µ

GND

16

4.2V

GND

GND

(13)

10.5k

50k

70k

17

GND

GND

(14)

10.5k

50k

70k

18

(15)

Vcc

147

GND

17.2k

1.5m

32k

32k

Vcc

19

– 5 –

CXA2020M/S

Pin No.

SDIP

SOP

Symbol

1620 ROUT 4.1V R-ch output.

1721 LOUT 4.1V

L-ch output.
During "TEST", the Cue
signal component
passed through the Cue
BPF is output.

1822 MCIN 4.1V

1923 MCOUT 3.4V

DC cut capacitor
connection of main
signal.

2025 SCIN 4.1V

2126 SCOUT 3.9V

DC cut capacitor
connection of sub
signal.

22

28 SUBI 4.1V

Bias capacitor
connection of sub FM
detector. "TEST" mode,
used for filter
adjustment, is
activated by grounding
this pin.

Pin

voltage

Equivalent circuit

Description

(22)

147

8k

64k

8k

Vcc

20µ80µ

16k

1.7V

4.2V

147

1k16k

Vcc

28

4.2V

147

80µ

20P

Vcc

80µ

GND

(21)

Vcc

147

147

26

(20)

Vcc

16k

25

4.2V

320µ

8k

40k

(19)

(18)

Vcc Vcc

147

147

16k

4.2V

147

160µ

147

80µ

80µ

20P

GND

Vcc

23

22

(17)

Vcc

147

GND

17.2k

1.5m

32k

32k

Vcc

21

(16)

Vcc

147

GND

17.2k

1.5m

32k

32k

Vcc

20

– 6 –

CXA2020M/S

Electrical Characteristics Measurement Circuit (CXA2020M)

CXA2020M

GND

SIGNAL

SIG

ATT

SW5

E1
9V

C2

47µF

C1

10µF

A

GND

C3

10µF

E5

C4

10µF

R2

910

STEREO

R3

910

SUB

R4

910

MAIN

GND

E4

GND

E3

GND

E2

SW1

SW2

SW3

15kHz
LPF

CCIR
FILTER

MEASUREMENT
SYSTEM

RMS
DISTORTION
DCVOLT

L OUT

R OUT

MAIN OUT

C10
1µF

C9

1µF

C10

10µF

ON

OFF

SW6

TEST

(ON)

NORM

(OFF)

SW4

∗

ATT is set to bring L → R stereo separation to a minimum.

15

16

17

18

19

20

21

22

23

24

25

26

27

28

2

3

4

5

6

7

8

9

10

11

12

13

14

1