PT2347
Stereo Audio Processor
Tel: 886-66296288‧Fax: 886-29174598‧ http://www.princeton.com.tw‧2F, 233-1, Baociao Road, Sindian, Taipei 23145, Taiwan
DESCRIPTION
The PT2347 is an audio processor designed for
versatile application, it adopts all of functions from
successful predecessor- the PT2313L, and it includes
3 stereo input selector with adjustable gain, master
volume control with low frequency loudness
compensation, individual output attenuator and tone
control.
In car audio applications, maximum power output of
the audio set is measurement on saturated condition, it
may not achieve the goal if power amplifier does not
have enough gain, therefore, the PT2347 provides
extra +10dB voltage gain in final output stage, it is
easy to drive the power amplifier into saturated power
and eliminates external gain OPAMP.
APPLICATIONS
• Car audio
• Home audio system
• Powered speaker system
FEATURES
• Controlled by I²C interface
• Direct replace the PT2313L with +10dB output gain
• 3 stereo inputs with gain selection, range from 0dB
to +11.25dB in 3.75dB/step
• Master volume from 0dB to -78.75dB in 1.25dB/step
• Speaker attenuator for balance and fader, range
from +10dB to -27.5dB in 1.25dB/step
• Each output can be muted individually.
• Low frequency loudness compensation
• Bass and Treble control, range from -14dB to
+14dB in 2dB/step
• Wide operation range (VDD=4V to 10V)
• Low harmonic distortion Low noise
BLOCK DIAGRAM
LOUT
LIN1
LIN2
LIN3
REF
LOUDNESS
LIN
LOUD_L
REF
BOUT_L
BIN_L
TREB_L
TREBLE
BASS
LFOUT
LROUT
REF
REF REF
REF
LOUDNESS
REF
TREBLE
BASS
RROUT
RFOUT
TREB_R
BOUT_R
LOUD_R
RIN
RIN3
RIN2
RIN1
ROUT
REF
VDD
REF
AGND
REF
SCL
SDA
DGND
I2C
DECODER
BIAS
BIN_R
Speaker Attenuator
With Mute
Master
Volume
Loud
SW
+10dB GAIN
+10dB GAIN
Input SW and
GAIN
Input SW and
GAIN
PT2347
V1.1 2 September 2010
APPLICATION CIRCUIT
1
2
3
4
5
6
7
8
9
10
11
12
13
14 15
16
17
18
19
20
21
22
23
24
25
26
27
28REF
VD D
AGND
TR EB_L
TR EB_R
RIN
RO UT
LOUD_ R
RIN3
RIN2
RIN1
LOUD_ L
LIN3
LIN2 LIN1
LIN
LOUT
BOUT _L
BIN_L
BIN_R
BOUT _R
RROUT
LROUT
RFOUT
LFOUT
DGND
SDA
SCL
2.2uF
2.2uF
22uF
VDD
2.7n
2.7n
100n
100n
100n
100n
100n
100n
5.6K
5.6K
Front Left
Front Right
Rear Left
Rear Right
10uF
10uF
10uF
10uF
Power
Amp lifier
2.2uF
2.2uF
2.2uF
2.2uF
2.2uF
2.2uF
AUDIO 1
AUDIO 2
AUDIO 3
2.2K
2.2K
2.2K
2.2K
2.2K
2.2K
L
L
L
R
R
R
Input Surge
Protection
PT2347