GL6840

5

GL6840B

Electronic Two Tone Ringer

Description

GL6840B are monolithic integrated circuits designed

to replace the mechanical bell in telephone sets,

in connection with an electro acoustical converter.

The device can drive either directly a piezo ceramic

converter(buzzer) or a small loudspeaker. In this

case a transformer is needed. The two tone frequen-

cies generated are switched by an internal oscillator

in a fast sequence and made audible across output

amplifiers in the transducer, both tone frequencies

and switching frequency can be externally adjusted.

The supply voltage is obtained from the AC rings

signal and the circuit is designed so that noise on the

line or variations on the ringing signal cannot affect

the correct operation of the devices.

The output bridge configuration allows to use a high

impedance transducer with acoustical results much

better than in a single ended configuration. The two

outputs can also be connected independently to

different converters or actuators(acoustical, opto and

logic)

Features

• Low current consumption, in order to allow the

parallel operation of 4 devices

• Integrated rectifier bridge with zener diodes to

protect against overvoltages

• Little external circuitry

• Tone and switching frequencies adjustable by

external components

• Integrated voltage and current hysteresis

• Bridge output configuration

Pin Configuration

Line

Rectifier

capacitor

Buzzer

Buzzer

Output freq.

Control resistor

Sweep rate

control capacitor

GND

Line

1

2

3

4

8

7

6

5

Absolute Maximum Ratings

Calling Voltage(f=50§ Ô

)

continuous

Calling Voltage(f=50§ Ô

)

5s ON/10s OFF

Supply Current

Operating Temperature

Storage Temperature

120Vrms

200Vrms

22§ Ì

-20 to 75¡ É

-65 to 150¡ É

GL6840B

8

5

7

1

2

3

4

6

Buzzer

39§ Ú

100§ Ý

£ «

10§ Þ

Line

1§ Þ 2.2§ Ú

(Top View)

Test Circuit

For GL6840B

R

)

x (2 - e

)

f

f

f

39 - R

§ Ú

)

358

1000

C

)