GL6840
GL6840B
Electronic Two Tone Ringer
Description
Pin Configuration
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)
8
7
6
5
Line
Line
1
2
3
4
Rectifier
GND
capacitor
Sweep rate
Buzzer
Buzzer
control capacitor
Output freq.
Control resistor
(Top View)
Absolute Maximum Ratings
Calling Voltage(f=50§ )Ô
continuous
120Vrms
200Vrms
Calling Voltage(f=50§ )Ô
5s ON/10s OFF
Supply Current
22§ Ì
-20 to 75¡ É
-65 to 150¡ É
Operating Temperature
Storage Temperature
Test Circuit
Features
3.32 x 104
R1(§ )Ú
)Ú
1
f1 =
x (2 - e 39 - R (§
)
For GL6840B
358
• Low current consumption, in order to allow the
parallel operation of 4 devices
• Integrated rectifier bridge with zener diodes to
protect against overvoltages
1000
C1(§ )Ý
fsweep
=
f2 = 0.717 x f1
1§ Þ 2.2§ Ú
Buzzer
• Little external circuitry
• Tone and switching frequencies adjustable by
external components
• Integrated voltage and current hysteresis
• Bridge output configuration
5
8
VAB Line
GL6840B
7
6
4
£ «
1
2
3
10§ Þ
VS
C1
R1
39§ Ú
100§ Ý
5