QS7779PM/CM

NIPPON PRECISION CIRCUITS—8

FUNCTIONAL DESCRIPTION

Operating Mode

This chip can be set to a desired operating mode by

control pins for the parallel interface (P/S pin sets to

HIGH) or control bits for the serial interface (P/S pin

sets to LOW). The control pins or bits configurations

are shown in the following table.

Note1.

× : Don’t care.

Note2. MUTE = 1 when PSAVE = 1

Mode description

Center signal output

CIN and COUT are used to emphasize the center signal.

How to use CIN and COUT.

s

Connect CIN and COUT with a resistor to make

the center signal emphasized.

s

Input resistance for CIN is 5k

Ω. For example, con-

necting a 5k

Ω resistor between CIN and COUT

makes output of (RIN+LIN)/2 to ROUT and

LOUT.

s

Directly connecting CIN and COUT makes ROUT

and LOUT output (RIN+LIN).

Mode

No.

Control Pins/Bits

Operation

(Output signal)

Description

B Y P

SPRD

MUTE

PSAV

E

LOUT

RO U T

11

×

0

0

LIN

R I N

Bypass mode

20000

QX(LIN)

QX(RIN)

Stereo enhanced and vir tual surround mode with low er enhanced

level

30100

QX+(LIN)

QX+(RIN)

Stereo enhanced and vir tual surround mode with higher enhanced

level

4

××

1

0

–

–

Mute mode

5

××

1

1

–

–

Pow er save mode. This function is available with serial interface only

Mode No.

Operating description

1

Bypass mode. Outputs the stereo signal as it is input.

2

Stereo Enhanced and vir tual surround mode with low er enhanced level. The Dolby Surround Pro Logic signal (Lt, Rt) input. Available

Surround Effect with two speakers by Qsurround technology. Virtual location of each signal is;

The Front signal: Virtually outside of the speakers.

The Rear signal: Virtually behind the listeners.

3

Stereo Enhanced and vir tual surround mode with higher enhanced level. The Dolby Surround Pro Logic signal (Lt, Rt) input. Available

Surround Effect with two speakers by Qsurround technology. This mode outputs the signals much more spread sound than Mode 2.

4

Mute mode. No signal at output pins.

5

P ow er save mode. This function is available with serial interface only.

Pin

Description

C I N

Outputs the doubled signal to ROUT and LOUT always.

COUT

Outputs the half level of signal ((RIN+LIN)/2).