The BA7757BK contains a playback equalizer amplifier, an REC / PB switch, a line amplifier, an ALC circuit with built-in detector, a recording amplifier, an analog switch for input switching, and a logic control circuit for independent switching of REC / EE, PR / EE, line mute and input.
The IC is easy to interface with control systems, and features low noise during mode switching and at power on / off. The line amplifier and recording amplifire are directly connected internally, allowing construction of a high-performance audio signal processing circuit for VCRs using a minimum number of external components.

FEATUREs
1) All necessary switches for audio signal processing are built-in.
    • MIC / LINE input selector switch.
    • EP / SP equalizer selector switch.
    • Built-in head switch on the playback side of the head for head switching for REC / PB, and a headswitch driver terminal provided on the recording side.
    • EE / PB and EE / REC selector switches (compatibility with after-recording mode (AFR) is possible).
    • Line muting switch.
2) All control functions are independent, so interfacing with the control system is simple.
3) Amplifiers required for audio recording and playback are provided on the IC.
4) Excellent S / N and distortion specifications through use of high-level ALC VR.
5) The ALC level is set using a external resistor, and variation due to temperature is extremely low.
6) Built-in ripple filter gives excellent ripple rejection.
7) Low noise generation when power is switched on and off, and during control system switching.
8) The line output can directly drive earphone.
9) Few external parts required.
10) Available in a QFP32 package, for high-density mounting.
11) Low power consumption.