STMICROELECTRONICS L3240B1

L3240
ELETRONIC TWO-TONE RINGER
.
.
..
.
.
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
COMPLEMENTARY OUTPUT CONFIGURATION
Minidip
SO8
ORDERING NUMBERS : L3240B1 (Minidip)
L3240D1 (SO8)
DESCRIPTION
L3240 is a monolithic integrated circuit designed to
replace the mechanical bell in telephone sets, in
connectionwith 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 sequenceand made audible across output amplifiers in the transducer ; both tone frequencies and
the switching frequency can be externally adjusted.
The supply voltage is obtained from the AC ring signal and the circuit is designed so that noise on the
line or variations of 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, logic).
June 1993
PIN CONNECTION ( top view)
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L3240
BLOCK DIAGRAM
ABSOLUTE MAXIMUM RATINGS
Symbol
VAB
VAB
DC
Top
Tstg
Parameter
Calling Voltage (f = 50 Hz) Continuous
Calling Voltage (f = 50 Hz) 5s N/10s OFF
Supply Current
Operating Temperature
Storage and Junction Temperature
Value
120
200
30
– 20, + 70
– 65, + 150
Unit
VRMS
VRMS
mA
o
C
o
C
THERMAL DATA
Symbol
Rth j-amb
Parameter
Value
Thermal Resistance Junction-ambient
Max.
Unit
o
100
C/W
ELECTRICAL CHARACTERISTICS
(Tamb = 25oC ; VS = applied between pins 7-2 ;otherwise specified)
Symbol
Vs
IB
VON
VOFF
RD
VOUT
IOUT
Vs
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Parameter
Supply Voltage
Current Consumption Without Load (Pins 8-1)
Activation Voltage
Sustaining Voltage
Differential Resistance in OFF Condition (Pins 8-1)
Output Voltage Swing
Short Circuit Current (pins 5-6)
Voltage Drop between Pins 8-1 and Pins 7-2
Test Conditions
Min.
V8-1 = 16.5 to 29.5 V
Typ.
1.5
12
7.8
6.4
Vs = 20 V
Vs – 5
35
3
Max.
26
1.8
13.5
9.3
Unit
V
mA
V
V
kΩ
V
mA
V
L3240
ELECTRICAL CHARACTERISTICS
(Tamb = 25oC ; VS = applied between pins 7-2 ;otherwise specified)
AC OPERATION
Symbol
Parameter
Output Frequencies
Fout 1
Fout 2
Fout 1
Fout 2
Programming Resistor Range
Sweep Frequency
Test Conditions
Vs = 26 V, R1 = 14 KΩ
Vs = 0 V
Vs = 6 V
R1 = 14kΩ, C1 =100nF
Min.
Typ.
Max.
2,29
1.6
2,8
2.1
1.33
1.43
8
5.25
56
9.75
7,5
Figure 1 : Test Circuit.
Figure 2 : Typical Application with Balanced
Output.
Figure 3 : Application Compatible with LS1240
(single ended output).
Figure 4 : F1 Out vs. R1.
4
R1 ≈ 3.56 x 10 x (1 – 0.12 x ln F1
F1 (HZ)
2543
)
f2 = 0.725 f1
fSWEEP =
Unit
kHz
kΩ
Hz
750
C1 (nF)
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L3240
MINIDIP PACKAGE MECHANICAL DATA
mm
DIM
Min.
A
Typ.
Max.
Min.
3.32
Typ.
Max.
0.131
a1
0.51
0.020
B
1.15
1.65
0.045
0.065
b
0.356
0.55
0.014
0.022
b1
0.204
0.304
0.008
0.012
E
10.92
7.95
9.75
0.430
0.313
0.384
e
2.54
0.100
e3
7.62
0.300
e4
7.62
0.300
DIP8.TBL
D
F
6.6
0260
i
5.08
0.200
L
Z
4/6
inch
3.18
3.81
1.52
0.125
0.150
0.060
L3240
SO8 PACKAGE MECHANICAL DATA
mm
DIM
Min.
Typ.
A
Max.
Min.
Typ.
1.75
0.1
0.069
0.25
a2
Max.
0.004
0.010
1.65
0.065
a3
0.65
0.85
0.026
0.033
b
0.35
0.48
0.014
0.019
b1
0.19
0.25
0.007
0.010
C
0.25
0.5
0.010
0.020
o
45 (typ.)
c1
D
4.8
5.0
0.189
0.197
E
5.8
6.2
0.228
0.244
e
1.27
0.050
e3
3.81
0.150
F
3.8
4.0
0.150
0.157
L
0.4
1.27
0.016
0.050
M
S
0.6
SO8.TBL
a1
inch
0.024
8 o (max.)
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L3240
Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for
the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its
use. No license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or
systems without express written approval of SGS-THOMSON Microelectronics.
 1994 SGS-THOMSON Microelectronics - All Rights Reserved
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