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LS1240 Dataheets PDF



Part Number LS1240
Manufacturers STMicroelectronics
Logo STMicroelectronics
Description ELECTRONIC TWO - TONE RINGER
Datasheet LS1240 DatasheetLS1240 Datasheet (PDF)

® LS1240A ELECTRONIC 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 Minidip DESCRIPTION LS1240A is a monolithic integrated circuit designed to replace the mechanical bell in telephone sets in connection with an electro-acous.

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® LS1240A ELECTRONIC 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 Minidip DESCRIPTION LS1240A is a monolithic integrated circuit designed to replace the mechanical bell in telephone sets in connection with an electro-acoustical converter. It can drive directly a piezoceramic converter (buzzer)or a dynamic loudspeaker. The output current capability of LS1240A is higher than standard ringer. For driving a dynamic loudspeaker LS1240A can simply use a decoupling capacitor, thus eliminating the usual transformer. No current limitation is provided on the output stage of LS1240A, so a minimum load DC of 50 Ω is adviced, in series with a proper capacitor. The two tone frequencies generated are switched by an internal oscillator in a fast sequence and made audible across an output amplifier in the loudspeaker, both tone frequencies and the switching frequency can be externally adjusted. PIN CONNECTION (top view) SO8 ORDERING NUMBERS Minidip LS1240A SO8 LS1240AD1 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 correct operation of the device. July 1998 1/7 LS1240A BLOCK DIAGRAM Figure 1 : Test Circuit. R1 = 2.72 ⋅ 104 f1 ⋅ ( 1 − 0.04 ln ) 1943 f1 (Hz) f2 = 0.725 f1 fSWEEP = 750 C1 (nF) 2/7 LS1240A ABSOLUTE MAXIMUM RATINGS Symbol VAB VAB DC Top Tstg Parameter Calling Voltage (f = 50 Hz) Continuous Calling Voltage (f = 50 Hz) 5s ON/10s OFF Supply Current Operating Temperature Storage and Junction Temperature Value 120 200 30 – 40 to + 70 – 65 to + 150 Unit Vrms Vrms mA °C °C THERMAL DATA Symbol Rth j-amb Parameter Thermal Resistance Junction-ambient Max Value 100 Unit °C/W ELECTRICAL CHARACTERISTICS (Tamb = 25 °C; Vs = applied between pins 7-2 unless otherwise specified) Symbol Vs IB VON VOFF RD VOUT IOUT 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 5-2) Vs = 20V RL = 250Ω V8-1 = 9.3 to 25 V 12.2 8 6.4 Vs – 5 70 1.5 Parameter Test Conditions Min. Typ. Max. 26 1.8 13.2 9 Unit V mA V V kΩ V mA AC OPERATION f1 f2 Output Frequencies fout1 fout2 fOUT1 fOUT2 Programming Resistor Range fSWEEP Sweep Frequency R1 = 14kΩ, C1 = 100nF Vs = 26V, R1 = 14kΩ Vs = 0 V Vs = 6V kHz 1.74 1.22 1.33 8 5.25 7.5 2.14 1.6 1.43 56 9.75 kΩ Hz 3/7 LS1240A Figure 2 : Typical Application with BUZZER Figure 3 : Typical Application with Loudspeaker (no transformer needed) C1 such that ZLOAD  > 1 ΚΩ 4/7 LS1240A MINIDIP PACKAGE MECHANICAL DATA DIM. MIN. A a1 B b b1 D E e e3 e4 F I L Z 3.18 7.95 2.54 7.62 7.62 6.6 5.08 3.81 1.52 0.125 0.51 1.15 0.356 0.204 1.65 0.55 0.304 10.92 9.75 0.313 0.100 0.300 0.300 0.260 0.200 0.150 0.060 mm TYP. 3.32 0.020 0.045 0.014 0.008 0.065 0.022 0.012 0.430 0.384 MAX. MIN. inch TYP. 0.131 MAX. 5/7 LS1240A SO8 PACKAGE MECHANICAL DATA DIM. MIN. A a1 a2 a3 b b1 C c1 D (1) E e e3 F (1) L M S 3.8 0.4 4.8 5.8 1.27 3.81 4.0 1.27 0.6 8° (max.) 0.15 0.016 5.0 6.2 0.65 0.35 0.19 0.25 0.1 mm TYP. MAX. 1.75 0.25 1.65 0.85 0.48 0.25 0.5 45° (typ.) 0.189 0.228 0.050 0.150 0.157 0.050 0.024 0.197 0.244 0.026 0.014 0.007 0.010 0.004 MIN. inch TYP. MAX. 0.069 0.010 0.065 0.033 0.019 0.010 0.020 6/7 LS1240A Information furnished is believed to be accurate and reliable. However, STMicroelectronics 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 STMicroelectronics. Specification mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics © 1998 STMicroelectronics – Printed in Italy – All Rights Reserved STMicroelectronics GROUP OF COMPANIES Australia - Brazil - Canada - China - France - Germany - Italy - Japan - Korea - Malaysia - Malta - Mexico - Morocco - The Netherlands Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A. 7/7 .


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