Princeton Technology Corp.
Tel: 886-2-29162151
Fax: 886-2-29174598
URL:
http://www.princeton.com.tw
Echo IC with Built-in Microphone Amplifier & Output Mixer
AUTO-VOCAL CHANGER APPLICATION CIRCUIT
AGND1
AGND2
MIC
IN
PT2390
+
4.7µF
AUTO VOCAL CHANGER DETAILED CIRCUIT
47K
1M
C945
5V
1M
MIC VOL2
4.7K
2
3
1
OUT_R
IN_R
RCA-JACK
10K
3900p
DGND
4 1/2LM358
15K
0.1µF
0.1µF
0.1µF
+
_
28
27
26
25
A
24
23
22
21
20
18
B
19
CC1
CC0
OP1_OUT
MIX2_OUT
OP2_OUT
17
16
AUTO VOCAL
CHANGER SENSITIVITY
LPF2_OUT
MIC2_OUT
ROUT
OP1_IN
OP2_IN
MIC2_IN
LPF2_IN
MIX2_IN
100K
VR
RIN
15
0.1µF
470K
10
11
12
13
14
8
1
2
3
4
5
6
7
9
LPF1_OUT
MIC1_OUT
ECHO_IN
VOCCON
LPF1_IN
MIC1_IN
MIX1_IN
CLK_IN
DGND
AGND
LOUT
VDD
REF
LIN
+
560p
PT2390
+
15K
TO A
10µF
3900p
15K
1N4148
47µF
1.5K
1µF
+
+
10µF
+
MIC VOL1
4.7K
OUT_L
RCA-JACK
IN_L
*5K
5V
0.1µF 220µF
+
10µF
A
10K
2
3
1
3
1
MIC
IN
Guidelines in using this Application Circuit:
1. IN_R must be connected to Human Vocal Input.
2. IN_L must be connected to KARAOKE Music
Note: * = You can adjust the 5K Variable Resistor value in order to change the Oscillator Frequency. The
Oscillator waveform can be measured from Pin No.12. It must be kept in mind that the
probe’s capacitor can cause erroneous oscillator waveform measurement.
Ref. No. 2390 v1.1
9
Written July 1999
+
1µF
0.01µF
2.7K
50K
ECHO VOL
47K
1M
2
10p
1µF
50K(SVR)
0.1µF
0.1µF
5V
8
560p
+
FEEDBACK
10µF
15K
1µF
10µF
10K
3K
0.01µF
5V
200K
+
+
+
+
+
+
PTC [ PRINCETON TECHNOLOGY CORP ]
