NPC QS7785CF, QS7785PF Datasheet

QS7785PF/CF

NIPPON PRECISION CIRCUITS INC.

3D 2/4-Channel Stereo Surround Synthesizer

OVERVIEW

The QS7785PF/CF is an audio processor IC that
generates 2, 4, 5-channel stereo surround signals
from 2-channel stereo or mono sources using QSur­round™ technology developed and licensed by
QSound Labs, Inc.

FEATURES

■

Surround signal output for 2-channel front speak­ers

■

Surround signal output for 4-channel front + sur­round speakers

■

Center speaker output for voice signals

■

Parallel and 2 serial interfaces for mode control
supported

APPLICATIONS

It can create 2-channel left and right surround effect
signal for front speakers, and a rich enhanced sur­round signal using front speakers and surround
speakers for 4-channel output. It also features a cen­ter signal output for clear listening of vocal and
speech signals.

• QS7785CF: I

2

C bus 2-wire serial interface

(Data and Clock)

• QS7785PF: 3-wire serial interface (Data, Clock
and Strobe)

■

5 to 13V analog supply

■

4.5 to 5.5V digital supply

■

48-pin QFP package

■

TV, radio and VCRs

■

Car audio

■

Multimedia products

PINOUT (Top view)

QS7785PF QS7785CF

FROUT

QXBC3

QXBC4

27

28

10

MONO

SP(STRB)

26

11

AC

FLOUT

25

24

23

22

21

20

19

18

17

16

15

14

13

12

BYP(SDA)

SROUT

SLOUT

COUT

CIN

LPC

VREFIN

N.C.

VREFOUT

PSAVE

MUTE

BASS

SUR(SCL)

RIN

LIN

BASC2

MSC6

MSC5

MSC4

MSC3

MSC2

MSC1

QXCC1

QXCC2

QXCC3

37

38

39

40

41

42

43

44

45

46

47

48

RIN

LIN

BASC2

MSC6

MSC5

MSC4

MSC3

MSC2

MSC1

QXCC1

QXCC2

QXCC3

BASC1

QXAC1

QXAC2

QXAC3

QXAC4

VCC

31

32

33

34

35

36

37

38

39

40

41

42

43

44

QS7785PF

45

46

47

48

123456789

QXDC2

QXDC3

GND

QXDC4

QXCC4

QXDC1

QXBC1

29

30

VDD

QXBC2

P/S

ORDERING INFORMATION

BASC1

QXAC1

QXAC2

QXAC3

QXAC4

VCC

QXBC1

QXBC2

QXBC3

28

29

30

31

32

33

34

35

36

QS7785CF

123456789

SP

P/S

VDD

QXDC2

QXDC3

GND

QXDC4

QXCC4

QXDC1

QXBC4

26

27

10

11

MONO

FROUT

FLOUT

25

12

AC

BYP(SDA)

24

SROUT

23

SLOUT

22

COUT

21

CIN

20

LPC

19

VREFIN

18

N.C.

17

VREFOUT

16

PSAVE

15

MUTE

14

BASS

13

SUR(SCL)

Device Package

QS7785PF 48-pin QFP

QS7785CF 48-pin QFP

2

I

C bus is a registered trademark of Philips Electronics N.V.

Dolby and the double-D symbol are registered trademarks of Dolby Laboratories Licensing Corporation.

NIPPON PRECISION CIRCUITS—1

PACKAGE DIMENSIONS

(Unit: mm)

QS7785PF/CF

0.20

0.20

7.00

9.00

0.50

BLOCK DIAGRAM

7.00

9.00

0.19

0.20

0.20

0.05

0.10

0.35max

0.08

0.17

0.05

0.339typ

0.20

0.10

0.07

1.50

0.10

M

1.00typ

0 to 10

0.50 0.10

BASC1

RIN

LIN

BASC2

MSC6

MSC5

MSC4

MSC3

MSC2

MSC1

VCC

VREFIN

GND

QXAC2

QXAC4

QXBC2

QXBC4

QXCC1

QXBC3

QXBC1

QXAC3

QXAC1

293234 27 46 48 2 4

28

30

33

36

37

38

39

40

41

42

43

44

45

31

19

6

17

To internal

18

35

Mono to

Stereo

To internal

Multiplex/Decode/Level Shift

16

15

14

10AC11

Front

QEXPANDER

Surround

QEXPANDER

9

13

12

QXCC3

QXCC247QXCC4

135

Serial I/O

7

8

QXDC1

QXDC2

QXDC3

QXDC4

26

25

24

23

21

22

20

FROUT

FLOUT

SROUT

SLOUT

CIN

COUT

LPC

N.C.

VREFOUT

MUTE

PSAVE

BASS

MONO

SP(STRB)

SUR(SCL)

BYP(SDA)

VDD

P/S

NIPPON PRECISION CIRCUITS—2

PIN DESCRIPTION

QS7785PF/CF

Number

I/O Description

Parallel Serial

1 QXCC4 O QEXPANDER C capacitor 4

2 QXDC1 I QEXPANDER D capacitor 1

3 QXDC2 O QEXPANDER D capacitor 2

4 QXDC3 I QEXPANDER D capacitor 3

5 QXDC4 O QEXPANDER D capacitor 4

6 GND – Ground

7 VDD – 4.5 to 5.5V digital supply

8 P/S I Input mode control (HIGH: parallel, LOW: serial)

SP – I Enhancement control (HIGH: high spread, LOW: low spread)

9

– STRB I Serial data strobe (not applicable to QS7785CF)

10 MONO I Mono-to-stereo convert select (HIGH: mono to stereo mode, LOW: normal mode)

11 AC I Center output control (HIGH: center on, LOW: center off)

BYP – I Bypass control (HIGH: bypass, LOW: Qsurround)

Name

12

– SDA I/O Serial data input (also serves as ACK signal output for I

2

C bus)

SUR – I Surround speaker control (HIGH: surround speaker on, LOW: off)

13

– SCL I Serial clock signal input

14 BASS I Bass boost mode control (HIGH: bass boost on, LOW: bass boost off)

15 MUTE I Mute signal control (HIGH: mute on, LOW: mute off)

16 PSAVE I Power save control (HIGH: power save on, LOW: power save off)

17 VREFOUT O V

/2 reference voltage output

CC

18 NC – No connection

19 VREFIN I V

/2 reference voltage output (biased internally to V

CC

/2)

CC

20 LPC I Center output lowpass filter

21 CIN I COUT output signal feedback input for front-channel output

22 COUT O Center signal output

23 SLOUT O Surround left-channel signal output

24 SROUT O Surround right-channel signal output

25 FLOUT O Front left-channel signal output

26 FROUT O Front right-channel signal output

27 QXBC4 O QEXPANDER B capacitor 4

28 QXBC3 I QEXPANDER B capacitor 3

29 QXBC2 O QEXPANDER B capacitor 2

30 QXBC1 I QEXPANDER B capacitor 1

31 VCC – 5 to 13V DC analog supply

32 QXAC4 O QEXPANDER A capacitor 4

33 QXAC3 I QEXPANDER A capacitor 3

34 QXAC2 O QEXPANDER A capacitor 2

35 QXAC1 I QEXPANDER A capacitor 1

36 BASC1 I Bass boost right-channel signal input

NIPPON PRECISION CIRCUITS—3

−

−

−

−

−

° C

−

° C

QS7785PF/CF

Number

I/O Description

Parallel Serial

37 RIN I Right-channel signal input

38 LIN I Left-channel signal input

39 BASC2 I Bass boost left-channel signal input

40 MSC6 I Mono/stereo conversion filter capacitor 6

41 MSC5 I Mono/stereo conversion filter capacitor 5

42 MSC4 I Mono/stereo conversion filter capacitor 4

43 MSC3 I Mono/stereo conversion filter capacitor 3

44 MSC2 I Mono/stereo conversion filter capacitor 2

45 MSC1 I Mono/stereo conversion filter capacitor 1

46 QXCC1 I QEXPANDER C capacitor 1

47 QXCC2 O QEXPANDER C capacitor 2

48 QXCC3 I QEXPANDER C capacitor 3

SPECIFICATIONS

Absolute Maximum Ratings

GND = 0V

Name

Parameter Symbol Rating Unit

Supply voltage range (analog) V

Supply voltage range (digital) V

Input voltage range (analog) V

Input voltage range (digital) V

2

I

C signal input voltage (SDA, SCL) V

Power dissipation P

Storage temperature range T

Recommended Operating Conditions

GND = 0V

Parameter Symbol Rating Unit

Supply voltage range (analog) V

Supply voltage range (digital) V

Operating temperature range T

CC

DD

IANA

IDIG

IOPEN

D

stg

CC

DD

opr

0.3 to 15 V

0.3 to 7 V

0.3 to V

+ 0.3 V

CC

0.3 to V

+ 0.3 V

DD

10 V

250 mW

40 to 125

5 to 13 V

4.5 to 5.5 V

20 to 85

NIPPON PRECISION CIRCUITS—4

DC Characteristics

V

= 9V, V

CC

= 5V, GND = 0V, Ta = 25 ° C

DD

−

−

QS7785PF/CF

Parameter Symbol Condition

Z

Analog input impedance

Reference voltage output V

HIGH-level input voltage V

LOW-level input voltage V

Input leakage current

LOW-level output voltage V

Supply voltage (analog) V

Supply voltage (digital) V

Current consumption (analog) I

Current consumption (digital) I

Standby current (analog) I

AIN1

Z

AIN2

REFOUT

IH

IL

I

LEAK

I

ILOPD

OL

CC

DD

CC

DD

CCSAVE

Noise and THD Characteristics

V

= 9V, V

CC

= 5V, GND = 0V, Ta = 25 ° C

DD

Rating

min typ max

LIN, RIN 16 20 24

CIN 8 10 12

–V

0.7V

DD

/2 – V

CC

––V

– – 0.3V

Digital inputs, V

SDA, SCL, 10V input voltage

ACK signal output from SDA, 3mA sink
current

input voltage

DD

3– 3

3– 3

0 – 0.4 V

5 – 13 V

4.5 – 5.5 V

–68mA

– 0.3 0.5 mA

– 0.1 0.2 mA

Unit

k Ω

DD

V

µA

Parameter Symbol Condition

Bypass noise voltage N

Qsurround noise voltage (front) N

Qsurround noise voltage (surround) N

Bypass total harmonic distortion THD

Qsurround mono total harmonic
distortion

THD

BYP = HIGH, SUR = MONO = SP = LOW,

BYP

“A”-wgt, FLOUT, FROUT

SUR = SP = HIGH, BYP = MONO = LOW,

QSF

“A”-wgt, FLOUT, FROUT

SUR = SP = HIGH, BYP = MONO = LOW,

QSR

“A”-wgt, SLOUT, SROUT

BYP = SUR = HIGH, MONO = SP = LOW,
LIN = RIN = 1V

B

FROUT, SLOUT, SROUT

, f = 1kHz, FLOUT,

RMS

BYP = LOW, SUR = MONO = SP = HIGH,
LIN = RIN = 1V

QM

FROUT, SLOUT, SROUT

, f = 1kHz, FLOUT,

RMS

Rating

Unit

min typ max

–1020µV

–2040µV

–1530µV

RMS

RMS

RMS

– – 0.1 %

– – 0.1 %

NIPPON PRECISION CIRCUITS—5