HEI GL6840B, GL6840A Datasheet

GL6840

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 frequen­cies 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)

Pin Configuration

Line 1

GND

Sweep rate
control capacitor

Output freq.
Control resistor

2

3

4

8

7

6

GL6840A

5

(Top View)

Absolute Maximum Ratings

Calling Voltage(f=50§Ô)
continuous
Calling Voltage(f=50§Ô)
5s ON/10s OFF
Supply Current
Operating Temperature
Storage Temperature

Line

Rectifier
capacitor

Buzzer

Buzzer

120Vrms

200Vrms

22§Ì

-20 to 75¡É

-65 to 150¡É

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

1

Test Circuit

For GL6840A

1§Þ 2.2§Ú

VAB Line

£«

10§Þ

3.26 x 10
R1(§Ú)

f2= 0.717 x f

8 5

GL6840A

7

1 2 3 4

VS

1

C1

100§Ý

4

x (2 - e )f1=

f

sweep

=

6

R1
14§Ú

14 - R1(§Ú)

95

1000

C1(§Ý)

Buzzer

Block Diagram

8

2

1

Sweep Frequency

Bridge
Diode

Oscillator

3 4

Overvoltage
Protection

Tone Generation

Oscillator

Threshold

Detector

Output

Stage

GL6840

7

5
6

Pin Description

PIN NAME DESCRIPTION

1,8 LINE

2 GND

3

4

5,6 Buzzer

7

Sweep Rate

Control Capacitor

Output Frequency

Control Resistor

Rectifier

Capacitor

Input terminals to bridge diode. The AC ringing signal from the
telephone line drives the ringer through bridge.

Ground

This pin is connected to external capacitor to control the sweeping
frequency(fSWEEP)

This pin is connected to external resistor to control the two tone
frequency(f1, f2)

The tone ringer output terminals which have inverse output phase
each others.

This pin is connected to external capacitor to change AC ringing
signal into DC voltage.

2

Electrical Characteristics : TA=25¡Éunless otherwise specified

GL6840

PARAMETER
Supply Voltage
Current Consumption without

load(pin 1-8)
Activation Voltage VON 14.4 V

Sustaining Voltage VOFF 9.7 V
Differential Resistance in

OFF condition(pin 8-1)

SYMBOL

CONDITIONS MIN. TYP. MAX.26UNIT

VS(pin7)

IB VS=16.5 to 29.5V 1.2 1.8

13.3

8.9

RD

12.3
8

6.4

§Ì

§Ú

Output Voltage Swing VOUT VVS-5
Short Circuit Current

(pin 5-6)
Voltage Drop between

pin 8-1 and pin 7-2
Output Frequencies

FOUT1
FOUT2

IOUT VS=20V 35

VD 3 V

VS=26V R1=14§Ú

F1
F2

VS=0V
VS=6V

1.96

1.42

2.3

1.67

2.65

1.92

§Ì

§Õ

V

Programming Resistor Range
Sweep Frequency

8 20
7 13FSWEEP C1=100§Ý 10

3

§Ú

§Ô