L6726

LINEAR INTEGRATED CIRCUIT

UNISONICTECHNOLOGIESCO.,LTD

11 of 13

www.unisonic.com.tw

QW-R108-015, C

APPLICATION INFORMATION(Cont.)

DESIGN PROCEDURE:

1. Circuit impedance to the line.

2. DC-characteristic

3. Gain regulation.

4. Transmitter gain and frequency response.

5. Receiver gain and frequency response.

6. Side-tone.

7. Components to suppress radio interference, specially the wires up to the handset.

Others:

The circuit can be placed either in the telephone or in the handset.

Cut off the transmitter can be done at F1 without interference of other functions of the circuit.

When using the extended low current and low voltage range (5mA, 2V), two resistors have to be connected from the

microphone inputs to ground as shown in fig. 13.

11

3

11

3

Fig. 7 Examples of network "2"

2

15

R10

R11

+Line

Fig. 8 Examples of network "4"

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3

11

3

11

3

11

3

11

3

11

3

2

15

+Line

R10

2

15

R10 +Line