SGS Thomson Microelectronics L3240D1, L3240B1 Datasheet

ELETRONIC TWO-TONERINGER

.LOW CURRENT CONSUMPTION, IN ORDER

TOALLOWTHEPARALLELOPERATIONOF4
DEVICES

.INTEGRATED RECTIFIER BRIDGE WITH

ZENER DIODES TO PROTECT AGAINST
OVERVOLTAGES

.LITTLEEXTERNAL CIRCUITRY

.TONE AND SWITCHING FREQUENCIES AD-

JUSTABLEBY EXTERNAL COMPONENTS

.INTEGRATED VOLTAGE AND CURRENT

HYSTERESIS

.COMPLEMENTARY OUTPUT CONFIGURA-

TION

L3240

Minidip SO8

ORDERINGNUMBERS : L3240B1 (Minidip)

L3240D1 (SO8)

DESCRIP TION

L3240is a monolithicintegratedcircuit designedto
replace the mechanical bell in telephone sets, in
connectionwithanelectroacousticalconverter.The
devicecandriveeitherdirectlyapiezoceramiccon­verter(buzzer)or a smallloudspeaker.In this case
a transformerisneeded. The two tone frequencies
generatedareswitchedby aninternaloscillatorin a
fastsequenceandmade audibleacrossoutputam­plifiersinthe transducer;bothtonefrequenciesand
the switching frequencycan be externallyadjusted.

ThesupplyvoltageisobtainedfromtheAC ringsig­nal and the circuit is designedso that noise on the
lineor variationsof the ringingsignal cannot affect
the correct operationof the devices.

Theoutputbridgeconfigurationallows to usea high
impedancetransducerwithacousticalresultsmuch
betterthan in a single endedconfiguration.

The two outputs can also be connected inde­pendently to different converters or actua­tors (acoustical,opto,logic).

June1993

PIN CONNECTION ( top view)

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L3240

BLOCK DIAG RAM

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V

AB

V

AB

DC Supply Current 30 mA
T

op

T

stg

Calling Voltage (f = 50 Hz) Continuous 120 V
Calling Voltage (f = 50 Hz) 5s N/10s OFF 200 V

Operating Temperature – 20, + 70
Storage and Junction Temperature – 65, + 150

o
o

THERMAL DATA

Symbol Parameter Value Unit

R

th j-amb

Thermal Resistance Junction-ambient Max. 100

o

C/W

ELECTRICAL CHARACTERISTICS

=25oC;VS= applied between pins 7-2 ;otherwise specified)

(T

amb

Symbol Parameter Test Conditions Min. Typ. Max. Unit

V

V

V

V

R

I

OUT

V

Supply Voltage 26 V

s

I

Current Consumption Without Load (Pins 8-1) V

B

Activation Voltage 12 13.5 V

ON

Sustaining Voltage 7.8 9.3 V

OFF

Differential Resistance in OFF Condition (Pins 8-1) 6.4 kΩ

D

Output Voltage Swing Vs–5 V

OUT

= 16.5 to 29.5 V 1.5 1.8 mA

8-1

Short Circuit Current (pins 5-6) Vs= 20 V 35 mA
Voltage Drop between Pins 8-1 and Pins 7-2 3 V

s

RMS
RMS

C
C

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