L6726
FUNCTIONAL DIAGRAM
1
DTMF
input
10
LINEAR INTEGRATED CIRCUIT
UTC L6726
AD
AT
AM
DC
8 9 7
AR
17
12
13
18
Telephone
Line
5
11
3
2
15
16 6
14
4
DC output for external
CMOS device
Mute
(active low)
3
1
5
2
4
1.Impedance to line and radio interference suppression.
2.Transmit gain and frequency response network.
3.Receive gain and frequency response network.
4.Side tone balance network.
5.DC-supply components.
MUTE
V
M
I
L
DTMF
600Ω
V
L
I
DC
+LINE
Z
MIC
=350
Ω
V3
R
L
=0~4KΩ
0
Ω
when artificail line is used
5H+5H
R
Load
=400Ω+400Ω
+
ARTIFICAIAL
LINE
C1
1μF
V2
V1
+
MIC
UTC 6726
with external
component
see fig 3
E=48.5V
REC
V
DC
-LINE
V4
Z
Rec
=350
Ω
C1= 1μF when artificial line is used
470μF when not used
Fig. 1 Test setup without rectifier bridge
MUTE
R
L
=0~4KΩ
5H+5H
R
Load
=400Ω+400Ω
+
V
M
Uz=(15 ~16)V
+
DTMF
600Ω
V
L
I
DC
I
L
+LINE
Z
MIC
=350
Ω
V3
C1
1μF
V2
V1
MIC
UTC 6726
with external
component
see fig 3
E=50V
REC
V
DC
-LINE
V4
Z
Rec
=350
Ω
Fig. 2 Test setup with rectifier bridge
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
4 of 13
QW-R108-015, C
UTC-IC [ UNISONIC TECHNOLOGIES ]
