Sony CXA2561Q Datasheet

Dolby∗B-C Type Noise Reduction System with Playback Equalizer Amplifier

Description

The CXA2561Q is an IC designed for use in car stereo cassette decks. Functions include Dolby B-C type noise reduction (NR) system, playback equalizer amplifier and music sensor into a single chip.

Features

• Few external parts

• Small package (40-pin QFP)

• Same pin configuration as for the Dolby B type NR

system (CXA2560Q) and no Dolby NR system

(CXA2559Q)

• Dolby B-C type NR and playback equalizer

amplifier into a single chip

• FORWARD/REVERSE head select switch

• Mute function

• Music signal interval detection level can be set by

the external resistors/capacitors (2 modes).

• High-frequency cut-off of the music sensor circuit

can be adjusted by the external capacitance.

CXA2561Q

40 pin QFP (Plastic)

Structure

Bipolar silicon monolithic IC

Absolute Maximum Ratings

• Supply voltage VCC 12 V

• Operating temperature Topr –40 to +85 °C

• Storage temperature Tstg –65 to +150 °C

• Power dissipation PD 430 mW

Operating Condition

Supply voltage VCC 7.8 to 11 V

Applications

• Car stereo cassette decks

• Playback-only cassette decks

∗

This IC is available only to the licensees of Dolby Laboratories Licensing Corporation from whom licensing and applications information may be obtained.

∗

"Dolby" and the double D symbols are trademarks of Dolby Laboratories Licensing Corporation.

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 –

E97439A79-PS

Block Diagram and Pin Configuration

CXA2561Q

PBFB2

PBRIN2

PBGND

PBFIN2

VCT

PBREF

PBFIN1

PBGND

PBRIN1

PBFB1

31

32

33

34

35

36

37

38

39

40

45k

PBTC2

30

1

7k/12k

300k

F2

30k

300k

7k/12k

PBOUT2

29

F1

2

OUTREF2

28

70µ/120µ

3

TAPEIN2

27

100k

×1

100k

4

T2

26

T1

5

GND

LPF

DIREF

25

24

BIAS

MUTE

TAPE EQ

FWD/RVS

VCC

F3

6

LINEOUT2

23

OFF/

B/C

OFF/

B/C

8

7

TCH2

NR

TCL2

21

22

MS MODE

NR MODE

MS ON/

OFF

DET

9

10

MSSW

20

19

18

17

16

15

14

13

12

11

MSMODE

DRSW

TAPESW

MUTESW

NRSW

NRMODE

MSOUT

MSTC

G1FB

G2FB

PBTC1

PBOUT1

TAPEIN1

OUTREF1

Vcc

NC

TCH1

LINEOUT1

TCL1

MSLPF

– 2 –

CXA2561Q

Pin Description (Ta = 25°C, VCC = 8.0V, DVCC = 5.0V)

Pin No.

1

30

Symbol

PBTC1 PBTC2

229PBOUT1

PBOUT2

Typical pin voltage

DC AC

4.0V —

4.0V –25dBm

I/O

resistance

——

I/O

O

—

Equivalent circuit Description

Vcc

Playback equalizer amplifier capacitance.

Vcc

Playback equalizer amplifier output.

30

29

147

1

GND

40

31

147

2p

200

300k

2

3

28

4

27

OUTREF1 OUTREF2

TAPEIN1 TAPEIN2

4.0V —

4.0V

–30dBm

GND

Vcc

200

O

I 100kΩ TAPE input.

—

27

28

4

3

200

GND

Vcc

147

100k

30p

Output reference. (Vcc/2 output)

VGS

GND

Vcc 8.0V5 — — — Power supply.

– 3 –

CXA2561Q

(Ta = 25°C, VCC = 8.0V, DVCC = 5.0V)

Pin No.

Symbol

724LINEOUT1

LINEOUT2

823TCH1

TCH2

Typical pin voltage

DC AC

4.0V –6dBm

0.3V —

I/O

resis-

Equivalent circuit Description

tance

Vcc

200

I/O

O — Line output.

24

——

8

23

147

7

147

200

36k

22.5k

GND

Vcc

Time constant for the HLS.

330k

922TCL1

TCL2

10 MSLPF — 100k

0.3V —

4.0V —

——

22

GND

Vcc

13.5k

147

9

480k

GND

Vcc

100k

147

10

64p

Time constant for the LLS.

Cut-off frequency adjustment of the music sensor LPF.

– 4 –

GND

CXA2561Q

(Ta = 25°C, VCC = 8.0V, DVCC = 5.0V)

Pin No.

Symbol

1112G2FB

G1FB

13

MSTC

Typical pin voltage

DC AC

4.0V —

—

I/O

resistance

——

I/O

—

Equivalent circuit Description

Vcc

147

11

12

853

147

13

500

GND

Vcc

Music signal interval detection level setting.

Time constant for detecting the music signal interval.

10k

GND

14 MSOUT

NRMODE

15

17 MUTESW

18

TAPESW

0.2V when a signal is detected; DVcc when no signal is detected.

0.0V when open.

—

O—

I 100kΩ

15 17 18

21

14

147

100k

Vcc

GND

Music sensor output.

Dolby NR mode control. Low (open):

High: Dolby C NR

Vcc

Mute function control. Low (open):

High: Mute ON Playback equalizer

amplifier control. Low (open): 70µs High: 120µs

Dolby B NR

Mute OFF

21

MSSW

Music sensor control. Low (open): MS ON High: MS OFF

– 5 –

CXA2561Q

(Ta = 25°C, VCC = 8.0V, DVCC = 5.0V)

No.

Symbol

Typical pin voltage

DC AC

16 NRSW

0.0V when

—

open.

19 DRSW

0.0V

20 MSMODE I

when

—

open.

I/O

resistance

I 100kΩ

100kΩ

I/O

Equivalent circuit Description

Vcc

Dolby NR control. Low (open):

High: NR ON

147

16

19

100k

Head select control. Low (open):

GND

High: REVERSE

Vcc

Music sensor mode

147

20

100k

control. Low (open): G1 High: G2

NR OFF

FORWARD

25 DIREF — —

26

GND

31

PBFB2

40

PBFB1

1.2V —

0.0V

4.0V

—

–70dBm

—

I—

3239PBRIN2

PBRIN1

—

34 37

PBFIN2 PBFIN1

4.0V

–70dBm

I

147

25

32

150 150

39

34

37

50p50p

GND

Vcc

GND

Vcc

GND

Resistance for setting the reference current. (Connects 20kΩ between DIREF pin and GND for the standerd setting.)

Ground.

Playback equializer amplifier feedback.

Playback equializer amplifier input.

31

(REVERSE head

40

connected)

Playback equializer amplifier input. (FORWARD head connected)

– 6 –