Audio ICs Recording amplifier with built-in ALC for headphone stereos BA3641FV The BA3641FV is an option IC developed for the purpose of adding a recording function to 1-chip playback system ICs (BA3612AKV, etc.) for headphone stereos. Applications Headphone stereos with recording function Features 1) Two built-in microphone amplifier channels. 2) Microphone mute function (radio / microphone switching). 3) Two built-in recording amplifier channels (with ALC). Absolute maximum ratings (Ta = 25C) Recommended power supply voltage ranges (Ta = 25C) 326 4) Two built-in monitor output amplifier channels (radio / microphone switching). 5) Built-in regulators for the erase head and bias OSC circuit. Audio ICs BA3641FV Block diagram 327 Audio ICs Pin descriptions 328 BA3641FV Audio ICs BA3641FV 329 Audio ICs BA3641FV Electrical characteristics (unless otherwise noted, Vcc = 2.3V, RF = 2.0V, +B = 1.2V, VREF = 1.0V, RL = 5kΩ, f = 1kHz, DIN-AUDIO, Ta = 25C) 330 Audio ICs BA3641FV 331 Audio ICs Measurement circuit Switch logic table 332 BA3641FV Audio ICs BA3641FV Application example 333 Audio ICs Electrical characteristic curves 334 BA3641FV Audio ICs BA3641FV 335 Audio ICs External dimensions (Units: mm) 336 BA3641FV