UTC1240A LINEAR INTEGRATED CIRCUIT ELECTRONIC DUAL-TONE RINGER DESCRIPTION The UTC1240A are monolithic integrated circuits designed to replace the mechanical bell in telephone sets in connection with an electro-acoustical converter.Both devices can drive directly a piezoceramic converter (buzzer). The output of UTC1240A needs a decoupling capacitor. SOP-8 No current limitation is provided on the output stage of UTC1240A,so a minimum load DC of 50 ohms is adviced. 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.The signal and the circuit is designed so that noise on the lin or DIP-8 variations of the ringing signal cannot affect correct operation of the device. FEATURES * Little external circuitry. * Low current consumption,in order to allow the parallel * Tone and switching frequencies adjustable operation of 4 devices. by external components. * Integrated rectifier bridge with zener diodes to protect * Intergrated voltage and current hysteresis against overvoltage. TEST CIRCUIT μF Ω 1 2.2k 8 VAB 5 UTC1240A 7 RL Vout μF 10 1 2 3 4 C1 100nF f1= 27200 R1(k Ω) f2=0.725f1 Ω R1 14k 750 f ( SWEEP )= C1(nF) YOUWANG ELECTRONICS CO.LTD 1 2005.08.25 V1.1 UTC1240A LINEAR INTEGRATED CIRCUIT ABSOLUTE MAXIMUM RATINGS(Ta=25°C) Characteristic Symbol Value Unit Calling voltage(f=50Hz) continuous VAB 120 Vrms Calling voltage(f=50Hz) 5s ON/10s OFF VAB 200 Vrms Supply Current IDC 30 mA Operating Temperature Topr -20~+70 °C Storage Temperature Tstg -65~+150 °C Rth-amb 200 °C /W Thermal resistance junction-ambient ELECTRICAL CHARACTERISTICS (Ta=25°C,unless otherwise specified) Characteristic Symbol Supply Voltage Vs Current consumption without load IB Test Conditions Min Typ Max 26 V 1.5 1.8 mA 13 14.5 V 9.3 Vs=9.3 to 25V Activation voltage VON Sustaining voltage VOFF 8.5 RD 6.4 Differential resistance in OFF condition Output voltage swing Vout Short circuit current Iout RL=250Ω Output high frequencies 1 fout1 V3=0V Output high frequencies 2 fout2 V3=6V Vs=26V,R1=14kΩ fout1/fout2 Programming resistor range Sweep frequency YOUWANG ELECTRONICS CO.LTD 2 V kΩ Vs-5 V 70 mA 1.55 2.53 1.08 1.9 kHz 1.33 1.43 kHz 56 kΩ 11.0 Hz 8 C1=100nF,R1=14kΩ Unit 8.0 9.5 kHz 2005.08.25 V1.1 UTC1240A LINEAR INTEGRATED CIRCUIT PIN CONFIGURATION LINE 1 8 LINE GROUND 2 7 RECTIFIER CAPACITOR SWEEP RATE CONTROL CAPACITOR 3 6 NULL OUTPUT FREQUENCY CONTROL RESISTOR 4 5 BUZZER TYPICAL APPLICATION μF μF Ω 1 1 2.2k 8 2.2k 5 Ω 8 5 CL LINE 7 LINE UTC1240A Ω 7 Zload>1k μF 10 1 2 3 UTC1240A Ω μF 10 1 4 C1 100nF Ω R1 14k 2 3 4 C1 100nF Figure.1 Ω RL=50 ~1000 BUZZER Ω R1 14k Figure.2 YOUWANG ELECTRONICS CO.LTD 3 2005.08.25 V1.1 UTC1240A LINEAR INTEGRATED CIRCUIT PACKAGE DIMENSIONS DIP-8-300-2.54 UNIT: mm SOP-8-225-1.27 UNIT: mm YOUWANG ELECTRONICS CO.LTD 4 2005.08.25 V1.1 UTC1240A LINEAR INTEGRATED CIRCUIT Attach Revision History Data 2005.08.25 REV Description 1.0 Original 1.1 Add “PACKAGE OUTLINE DIP-8,SOP-8” YOUWANG ELECTRONICS CO.LTD 5 Page 4 2005.08.25 V1.1