UTCL6726

LINEAR INTEGRATED CIRCUIT

5

QW-R108-015,A

+LINE

-LINE

REC

MUTE

V4

DTMF

C1

1μF

600Ω

V1

V2

Figure 2. Test setup with rectifier bridge

5H+5H

E=50V

Uz=(15 ~16)V

MIC

V3

=400Ω+400Ω

UTC 6726

with external

component

see fig 3

+

+

C8

220nF

10

12

13

DC

7

9

8

C7

47μF

R5

22k

511

3

2

C3

100nF

R6

75 Ω

R9

11k

R8

R7

910 Ω

C4

47nF

R11

C5

R13

11k

R15

10 Ω

15 14 6

14 4

R1

R2

47μF

910 Ω R3

C2

15nF

R14

310Ω

R10

*

*

17

18

AR

AT

AM

1

UTC 6726

+Line

-Line

DTMF

input

MIC

350Ω

DC supply OUT

CMOS device

Sense input

Control output

AD

R4

18k

560Ω

3kΩ

MUTE

100nF

Note : * Not used in test setup

Figure 3. Circuit with external components for test setup.

82k

REC

350 Ω

C1

+

+

R16

27k

FUNCTIONAL DESCRIPTION

The gain of the transmitting and receiving amplifiers are continuously and euqually changed with the line length.

The starting point for the gain regulation is externally set .The gain regulation can be cut-off externally, see table

under gain regulation below.

The outputs of the transmitting and receiving amplifiers have internals limitations of the output amplitudes.