IL6840

Figure2 : Single output applied pin#6

1 F, 250V

0.22 F

2.2 K

AC

DESCRIPTION

The IL6840 tone ringer derives its power supply by rectifying the AC ringing signal. It uses this power to activate

two tone generators. The two tone frequencies generated are switched by internal oscillator in a fast sequence and made

audible across an output amplifier in the loudspeaker; both tone frequencies and the switching frequency can be

externally adjusted.

The device can drive either directly a piezo ceramic converter (buzzer) or small loudspeaker. In case of using a

loud-speaker, a transformer is needed.

An internal shunt voltage regulator provides DC voltage to the output stage, low frequency oscillator, and high

frequency oscillator. To protect the IC from telephone line transients, a zener Diode is included.

RING

TIP

R

2

C

2

10K

10K

10 F

3

100nF

14K

C

R

1

IL6840

5

6

7

TEL

Piezo

2

3

1

4

1300:8

VS

8

4