Audio ICs Dual preamplifier with ALC detector circuit BA3314F The BA3314F is a dual preamplifier IC with built-in ALC detector circuit, designed for audio applications. It comes in a compact 14-pin SOP package, and has two record / playback preamplifiers, and an ALC detector circuit. The preamplifier can be directly coupled to the tape head without coupling capacitors to prevent tape head magnetization and “pop” noise generation. With the built-in ALC detector circuit, an ALC circuit with large dynamic range can be constructed with addition of just an external time constant circuit. Applications Audio equipment Features 1) Input bias circuit does not require coupling capacitors. 2) Built-in ALC circuit with external time constant circuit. 3) Wide operating power supply voltage range. 4) High gain. 5) Low noise. Block diagram 217 Audio ICs FAbsolute maximum ratings (Ta = 25_C) FRecommended operating conditions (Ta = 25_C) FElectrical characteristics (unless otherwise noted, Ta = 25_C, VCC = 8V and f= 1kHz) 218 BA3314F Audio ICs BA3314F Measurement circuit Operation notes Changing the input resistor R g , and the ALC time constant influences the ALC transient characteristics. In particular, if Rg is less than 3.9kΩ or the time constant capacitor is less than 47µF, the ALC may operate excessively. Do not use smaller values than those recommended for these components. 219 Audio ICs BA3314F Application example Electrical characteristics curve 220 External dimensions (Units: mm)