UTC L388 12 LINEAR INTEGRATED CIRCUIT

2

QW-R108-013,A

PIN DESCRIPTIONS

16-pin

SO

18-pin

DIP

SYMBOL

DESCRIPTION

1

16

CTR

Control input for gain dynamics (25 or 50dB), mute and disable.

2

17

-Txin

Transmitter channel negative input. Input impedance 3kΩ.

3

18

+Txin

Transmitter channel positive input. Input impedance 100kΩ.

4

1

F2out

Output of the second amplifier in the transmitter channel.

5

2

Txout

Transmitter channel output. Min. ac load impedance 10kΩ.

6

3

TxDetin

Input of the transmitter channel signal detector. Input impedance 13kΩ.

7

4

TxDetout

Output of the transmitter channel signal detector. Goes negative referred

to the internal ref. voltage of app.2V when a transmitter signal is present.

8

5

NDet

Background noise detector output. Goes positive referred to the internal

ref. Voltage of app.2V when a background noise signal is present.

9

6

CMP

Comparator input..

Summing point to the different Detector outputs.

10

7

RxDetout

Output of the receiver channel signal detector. Goes positive referred to

the internal ref. Voltage of app.2V when a receiver signal is present

11

8

RxDetin

Input of the receiver channel signal detector. Input impedance 13kΩ.

12

9

Rxout

Receiver channel output. Min. ac load impedance 10kΩ.

13

10

F5out

Output of the second amplifier in the receiver channel.

11

+Rxin

Receiver channel positive input. Input impedance 140kΩ.

14

12

-Rxin

Receiver channel negative input,Input impedance 20kΩ.

15

13

V+

Supply of the speech switching circuitry. A shunt regulator, voltage

apprx. 3.3V at 1.0mA.

16

14

GND

System ground.

15

NC

Not connected.

BLOCK DIAGRAM(16-pin SO package)

1

13

16

12

11

14

10

9

7

8

3

2

15

6

4

5

F3

F2

-

+

F6

F5

F4

Ref.

Control

F1

+

+