GL6840
1
GL6840A
Electronic Two Tone Ringer
Description
GL6840A 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
)
continuous
Calling Voltage(f=50
)
5s ON/10s OFF
Supply Current
Operating Temperature
Storage Temperature
120Vrms
200Vrms
22
-20 to 75
-65 to 150
GL6840A
8
5
7
1
2
3
4
6
Buzzer
R
1
14
C
1
100
V
S
10
V
AB
Line
1
2.2
GL6840A
(Top View)
Test Circuit
For GL6840A
3.26 x 10
4
R
1
(
)
x (2 - e )
f
1
=
f
2
= 0.717 x f
1
f
sweep
=
14 - R
1
(
)
95
1000
C
1
(
)
GL6840
2
Block Diagram
Pin Description
Threshold
Detector
Sweep Frequency
Oscillator
Tone Generation
Oscillator
Output
Stage
Overvoltage
Protection
Bridge
Diode
8
1
3
4
5
6
7
2
PIN
NAME
DESCRIPTION
1,8
LINE
Input terminals to bridge diode. The AC ringing signal from the
telephone line drives the ringer through bridge.
2
GND
Ground
3
Sweep Rate
Control Capacitor
This pin is connected to external capacitor to control the sweeping
frequency(f
SWEEP
)
4
Output Frequency
Control Resistor
This pin is connected to external resistor to control the two tone
frequency(f
1
, f
2
)
5,6
Buzzer
The tone ringer output terminals which have inverse output phase
each others.
7
Rectifier
Capacitor
This pin is connected to external capacitor to change AC ringing
signal into DC voltage.
GL6840
3
Electrical Characteristics : T
A
=25
unless otherwise specified
PARAMETER
Supply Voltage
SYMBOL
V
S
(pin7)
CONDITIONS
MIN.
TYP.
MAX.
26
UNIT
V
Current Consumption without
load(pin 1-8)
I
B
V
S
=16.5 to 29.5V
1.2
1.8
Activation Voltage
V
ON
14.4
V
Sustaining Voltage
V
OFF
9.7
V
13.3
8.9
12.3
8
Differential Resistance in
OFF condition(pin 8-1)
R
D
6.4
Output Voltage Swing
V
OUT
V
V
S
-5
Short Circuit Current
(pin 5-6)
I
OUT
V
S
=20V
35
Voltage Drop between
pin 8-1 and pin 7-2
V
D
3
V
Output Frequencies
F
OUT1
F
OUT2
F
1
F
2
V
S
=26V R
1
=14
V
S
=0V
V
S
=6V
1.96
1.42
2.3
1.67
2.65
1.92
Programming Resistor Range
8
20
Sweep Frequency
7
13
F
SWEEP
C
1
=100
10
GL6840
4
Typical Application
Figure1 : Single output applied pin#5
Figure2 : Single output applied pin#6
Note) Using a big size buzzer, pin#6 output is better than pin#5 output.
Figure3 : Differential output
GL6840A
8
5
7
1
2
3
4
R
1
14
C
1
100
V
S
10
V
AB
Tel Line
1
250V AC 2.2
C
2
R
2
C
3
RING
TIP
6
Vout
Piezo
10
10
0.22
Speaker
1300:8
C
C
C C
C
C
C
C
GL6840A
8
5
7
1
2
3
4
R
1
14
C
1
100
V
S
10
V
AB
Tel Line
1
250V AC
2.2
C
2
R
2
C
3
RING
TIP
6
Vout
Piezo
10
0.22
10
Speaker
1300:8
C
C C
C
C
C
C
C
GL6840A
8
6
7
1
2
3
4
R
1
14
C
1
100
V
S
10
V
AB
Tel Line
1
250V AC
2.2
C
2
R
2
C
3
RING
TIP
5
Piezo
10
10
0.22
Speaker
1300:8
C
C
C
C
C
C
C
C
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
)
continuous
Calling Voltage(f=50
)
5s ON/10s OFF
Supply Current
Operating Temperature
Storage Temperature
120Vrms
200Vrms
22
-20 to 75
-65 to 150
GL6840B
8
5
7
1
2
3
4
6
Buzzer
R
1
39
C
1
100
V
S
10
V
AB
Line
1
2.2
GL6840B
(Top View)
Test Circuit
For GL6840B
3.32 x 10
4
R
1
(
)
x (2 - e )
f
1
=
f
2
= 0.717 x f
1
f
sweep
=
39 - R
1
(
)
358
1000
C
1
(
)
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