KA2418B/28 TONE RINGER WITH BRIDGE DIODE
INTRODUCTION
The KA2418B/28 is a monolithic integrated circuit telephone tone
ringer with bridge diode, when coupled with an appropriate
transducer, it replaces the electromechanical bell. This device is
designed for use with either a piezo transducer or an inexpensive
transformer coupled speaker to produce a pleasing tone composed
of a high frequencys (f
H1
, f
H2
) alternating with a low frequency (f
S
)
resulting in a warble frequency. The supply voltage is obtained from
the AC ring signal and the circuit is designed so that noise on the
line or variation of the ringing signal can not affect correct operation
of the device.
FEATURES
Built-in full wave bridge diode rectifier
Low current consumption, in order to allow the
parallel operation of the 4 devices
Few external components
Tone and adjustable switching frequencies by
external components
High noise immunity due to built-in voltage to
current hysteresis
Adjustable activation voltage
Internal zener diodes to protect against over
voltages
Adjustable ringer impedance with external
components.
BLOCK DIAGRAM
Fig. 1
Device
Package
Operating Temperature
KA2418B
KA2428
8
1
7
-
+
2
POWER
SUPPLY
CONTROL
CIRCUIT
6
3
5
LOW
FREQ OSC
HIGH
FREQ OSC
OUTPUT
AMP
4
TIP
RING
GND
SWEEP RATE
CONTROL
CAPACITOR
OUTPUT FREQUENCY
CONTROL RESISTOR
OUTPUT
ACTIVATION
VOLTAGE ADJUSTABLE
RECTIFIER
CAPACITOR
8-DIP-300
- 20
C ~ + 70
C
8-DIP-300
ORDERING INFORMATION
APPLICATIONS
Electronic telephone ringers
Extension ringers
KA2418B/28 TONE RINGER WITH BRIDGE DIODE
ABSOLUTE MAXIMUM RATINGS
Absolute maximum ratings are those values beyond which permanent damage to the device may occur. These
are stress ratings only and functional operation of the device at or beyond them is not implied. Long exposure
to these conditions may affect device reliability.
DC ELECTRICAL CHARACTERISTICS
(T
a
= 25
C)
AC ELECTRICAL CHARACTERISTICS
(T
a
= 25
C)
Characteristic
Symbol
Value
Unit
Calling Voltage (f = 50H
Z
) Continuous
Calling Voltage (f = 50H
Z
)
5 Sec ON/10 Sec OFF
Supply Current
Operating Temperature
Storage and Junction Temperature
V
C
V
C(0N-OFF)
I
CC
T
ORR
T
STG
120
200
22
-20 ~ +70
-65 ~ +150
Vrms
Vrms
mA
C
C
Characteristic
Symbol
Test Conditions
Min
Typ
Max
Unit
Operating Voltage
V
CC
-
-
-
26
V
Current Consumption without Lode
I
CC
V
S
= 8.8 to 26V
-
1.5
1.8
mA
Activiation Voltage
V
ON
-
12.2
-
13
V
Activiation Voltage Range
V
ONR
R
A
= 1K
8
-
10
V
Sustaining Voltage
V
SUS
-
8
-
8.8
V
Differential Resistance in off Condition
R
D(OFF)
-
6.4
-
-
K
Output Voltage Swing
V
0(P-P)
-
-
V
CC
-3
-
V
Short Circuit Current
I
SC
V
S
= 26V
-
35
-
mA
Characteristic
Symbol
Test Conditions
Min
Typ
Max
Unit
Output Frequencies (KA2418B)
V
CC
= 26V,R
1
= 14K
V
CC
= OV
V
CC
= 6V
-
2300
1700
-
-
H
Z
H
Z
Output Frequencies (KA2428)
V
CC
= 26V,R
1
= 14K
V
CC
= OV
V
CC
= 6V
-
1900
1300
-
-
HZ
HZ
f
H1
Range
f
H1R
R
1
=27K
to 1.7K
0.1
-
15
KH
Z
Sweep Frequency
f
S
R
1
=14K
, C1=100nF
-
10
-
H
Z
f
H1
f
H2
f
H1
f
H2
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