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 QSur-
round™ technology developed and licensed by
QSound Labs, Inc.
It can create 2-channel left and right surround effect
signal for front speakers, and a rich enhanced sur-
round signal using front speakers and surround
speakers for 4-channel output. It also features a cen-
ter signal output for clear listening of vocal and
speech signals.
FEATURES
I
I
I
I
Surround signal output for 2-channel front speak-
ers
Surround signal output for 4-channel front + sur-
round speakers
Center speaker output for voice signals
Parallel and 2 serial interfaces for mode control
supported
I
I
I
• 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
APPLICATIONS
I
I
TV, radio and VCRs
Car audio
I
Multimedia products
PINOUT
(Top view)
QS7785PF
FROUT
FLOUT
QXAC1
QXAC2
QXAC3
QXAC4
QXBC1
QXBC2
QXBC3
QXBC4
QS7785CF
FROUT
26
QXAC1
QXAC2
QXAC3
QXAC4
QXBC1
QXBC2
QXBC3
36
35
34
33
32
31
30
29
28
27
26
25
36
35
34
33
32
31
30
29
28
27
QXBC4
BASC1
BASC1
VCC
VCC
RIN
LIN
BASC2
MSC6
MSC5
MSC4
MSC3
MSC2
MSC1
QXCC1
QXCC2
QXCC3
37
38
39
40
41
42
43
44
45
46
47
48
10
11
12
1
2
3
4
5
6
7
8
9
24
23
22
21
20
19
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
25
FLOUT
24
23
22
21
20
19
37
38
39
40
41
42
43
44
45
46
47
48
10
11
12
1
2
3
4
5
6
7
8
9
SROUT
SLOUT
COUT
CIN
LPC
VREFIN
N.C.
VREFOUT
PSAVE
MUTE
BASS
SUR(SCL)
QS7785PF
18
17
16
15
14
13
QS7785CF
18
17
16
15
14
13
SP(STRB)
BYP(SDA)
ORDERING INFORMATION
Device
QS7785PF
QS7785CF
Package
48-pin QFP
48-pin QFP
I
2
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
BYP(SDA)
QXDC1
QXDC2
QXDC3
QXDC4
QXDC1
QXDC2
QXDC3
QXDC4
QXCC4
QXCC4
VDD
MONO
VDD
MONO
GND
P/S
GND
P/S
AC
SP
AC
NPC [ NIPPON PRECISION CIRCUITS INC ]
