DUAL RECORDING/PLAYBACK PREAMPLIFIER CIRCUIT WITH ALC IT7312 DESCRIPTION The IT7312 is a monolithic integrated circuit designed for dual pre-amplifier circuit with ALC for recording/playback amplifier of cassette tape recorder. FEATURES *High open loop gain *Incorporates ALC detector circuit *No input coupling condenser *Low noise and current consumption *Wide ALC range *Wide operating voltage range: Vcc=5V~12V *Low power on shock noise BLOCK DIAGRAM 14 13 12 11 10 RIPPLE FILTER 9 8 6 7 AMP CH1 ALC AMP CH2 1 I-TECH TECHNOLOGY LIMITED www.it-semiconductor.com 2 3 4 5 Page 1 of 4 DUAL RECORDING/PLAYBACK PREAMPLIFIER CIRCUIT WITH ALC ABSOLUTE MAXIMUM RATINGS IT7312 (Tamb=25℃) CHARACTERISTIC SYMBOL VALUE UNIT Supply Voltage Vcc 14 V Supply Current Icc 50 mA Power Dissipation PD 700 mW Operating Temperature Topr -55 to +125 ℃ Storage Temperature Tstr -65 to +150 ℃ ELECTRICAL CHARACTERISTICS (Tamb=25℃, Vcc=6V, f=1KHz, unless otherwise specified) CHARACTERISTIC SYMBOL TEST CONDITION MIN TYP MAX UNIT Quiescent Current Iccq Vin=0 2.5 4.5 8.0 mA Operating Voltage Vcc 12.0 V Closed Loop Voltage Gain Gv Vo=0.5V 69 72 dB Total Harmonic Distortion THD Vo=0.5V 0.5 1.0 % Output Voltage Vo THD=1% Output Noise Voltage VNO Rg=0(internal resistance 1.5kΩ DIN/Audio) ALC Voltage VALC Vin=400μV ALC Width WALC ALC Balance ΔGv I-TECH TECHNOLOGY LIMITED www.it-semiconductor.com 5.0 66 1.2 1.6 V 2.0 5.0 mV 0.55 0.63 0.7 V Beginning 0dB to 3dB 35 47 Vo=0.5V -1 0 dB +1 dB Page 2 of 4 DUAL RECORDING/PLAYBACK PREAMPLIFIER CIRCUIT WITH ALC IT7312 APPLICATION CIRCUIT IT7312 I-TECH TECHNOLOGY LIMITED www.it-semiconductor.com Page 3 of 4 DUAL RECORDING/PLAYBACK PREAMPLIFIER CIRCUIT WITH ALC IT7312 OUTLINE DRAWING I-TECH TECHNOLOGY LIMITED www.it-semiconductor.com Page 4 of 4