datasheetbank_Logo
Integrated circuits, Transistor, Semiconductors Search and Datasheet PDF Download Site

QS7785CF View Datasheet(PDF) - Nippon Precision Circuits

Part Name
Description
View to exact match
QS7785CF
NPC
Nippon Precision Circuits  NPC
QS7785CF Datasheet PDF : 15 Pages
First Prev 11 12 13 14 15
QS7785PF/CF
Center Control
The center signal output on COUT is enabled when
AC is HIGH.
This section describes the output function whereby
fixed frequency sound sources, such as vocal and
speech signals, can be output on the center signal. As
mentioned for “Type C” and “Type D” speaker
arrangements, the center signal can be output by
direct connection to a speaker or by adding the signal
to the front-channel output using a resistor connec-
tion between CIN and COUT.
Using a center speaker
When using a speaker, a capacitor Ca can be con-
nected between LPC and COUT, forming a lowpass
filter. The 3dB cutoff frequency of the filter is given
by the following equation.
f = 2----π----C----a-1---×-----R----1--
Adding to the front-channel output
With this connection, the bass frequency components
can be removed from a signal. Capacitors Ca and Cb
and resistor Ra can be connected between CIN and
COUT to form a highpass filter. The 3dB cutoff fre-
quency of the filter is given by the following equa-
tion.
f = 2----π----C----b---(---R-1---a----+-----R----2----)
The input signal on CIN is added equally to both
front-channel outputs FLOUT and FROUT. Frequen-
cies lower than voice tones are cut from the signal
added to the front-channel outputs for clear repro-
duction of voice-band signals.
Frequencies higher than voice tones are cut from the
signal sent to the center speaker for clear reproduc-
tion of voice-band signals.
Close when AC=H
Open when AC=L
R1:20k
LPC
20
Ca
22
COUT
Close when MUTE=H
Open when MUTE=L
R3:10k
Ra:10k CIN
10k
21
R2:10k
10k
VREFOUT
FROUT
26
10k
10k
FLOUT
25
Front Right
Speaker
Cnter
Speaker
Front Left
Speaker
Center output connection
Gain V(COUT)/V(RIN)@V(LIN)=0
6dB
3dB
GC
3dB
fL=
1
2πCb(Ra+R2)
fH=
1
2πCaR1
( ) GC=20 log
R3
Ra+R2
6dB
V(FROUT)
or V(FLOUT)
Freq.
fL
fH
Center output frequency response
Note: Internal resistance value, R1 and R2, may vary ± 15%.
NIPPON PRECISION CIRCUITS—11
 

Share Link: 

datasheetbank.com [ Privacy Policy ] [ Request Datasheet ] [ Contact Us ]