Preliminary PT2347 Stereo Audio Processor DESCRIPTION FEATURES 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. • 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 0dB to -38.75dB 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 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 BLOCK DIAGRAM Speaker Attenuator With Mute RROUT LROUT REF +10dB GAIN REF +10dB GAIN RFOUT LFOUT REF TREB_L REF TREBLE Master Volume BIN_L BASS BOUT_L REF LOUD_L TREB_R TREBLE Loud SW BIN_R BASS BOUT_R REF LOUDNESS LOUD_R LOUDNESS RIN LIN ROUT LOUT Input SW and GAIN LIN1 Input SW and GAIN RIN1 LIN2 RIN2 LIN3 RIN3 REF REF VDD REF SCL REF BIAS I2C DECODER SDA DGND AGND Tel: 886-66296288‧Fax: 886-29174598‧ http://www.princeton.com.tw‧2F, 233-1, Baociao Road, Sindian, Taipei 23145, Taiwan PT2347 APPLICATION CIRCUIT DIAGRAM PT2347 22uF VDD 1 REF SCL 28 2 SDA 27 VDD 3 AGND 27n 27n Input Surge P rotection L A UDIO 3 R L A UDIO 2 R L A UDIO 1 R PRE1.0 2.2uF 2.2K 2.2uF 2.2K 2.2uF 2.2K 2.2uF 2.2K 2.2uF 2.2K 2.2uF 2.2K 2.2uF TREB_L LFOUT 25 5 TREB_R RFOUT 24 6 RIN LROUT 23 7 ROUT RROUT 22 8 LOUD_R 100n 9 RIN3 BOUT_R 21 BIN_R 20 10 RIN2 BOUT_L 19 11 RIN1 BIN_L 18 12 LOUD_L 100n DGND 26 4 LOUT 17 13 LIN3 LIN 16 14 LIN2 LIN1 15 10uF Front Left 10uF 10uF Front Right 10uF 100n 5.6K 100n 100n 100n 2.2uF Rear Left 5.6K Rear Right P ower A mplifier 2 PT2347 ORDER INFORMATION Valid Part Number PT2347-S Package Type 28 Pins, SOP, 300mil Top Code PT2347-S PIN CONFIGURATION PIN DESCRIPTION Pin Name REF VDD AGND TREB_L TREB_R RIN ROUT LOUD_R RIN3 RIN2 RIN1 LOUD_L LIN3 LIN2 LIN1 LIN LOUT BIN_L BOUT_L BIN_R BOUT_R RROUT LROUT RFOUT LFOUT DGND SDA SCL PRE1.0 I/O I I I O I I I I I I I I I O I O I O O O O O I I Description Analog reference voltage (1/2VDD) Supply input voltage Analog ground Left channel input for treble controller Right channel input for treble controller Right channel volume controller input Right channel Input selector output Right channel loudness input Right channel input 3 Right channel input 2 Right channel input 1 Left channel loudness input Left channel input 3 Left channel input 2 Left channel input 1 Left channel volume controller input Left channel Input selector output Left channel input for bass controller Left channel output for bass controller Right channel input for bass controller Right channel output for bass controller Right rear speaker output Left rear speaker output Right front speaker output Left front speaker output Digital ground I2C data input I2C clock input Pin No. 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 28 3