The BA7181FS is a PRE / REC amplifier developed for use in video cassette recorders. It has been designed for use in two-head decks and features built-in FB damping, two preamplifiers, a chroma output amplifier, an FM output amplifier (with AGC), an envelope detector, a constant-current BTL-drive REC amplifier (with AGC)and built-in chan nel and REC / PB switches on a single monolithic IC.
1) The playback amplifier has a total gain of 57dB (Typ.), and has a low-noise preamplifier. Designed for VHS-band operation with low external parts count. The IC has two circuits for two-head VCR applications.
2) Two playback output systems (through output and AGC output). The AGC output level is 300mVP-P(Typ.); suitable for FM brightness signal output.
3) Auto-tracking interface is provided for automated tracking adjustment. The detector characteristic is linear, and the sensitivity can be adjusted using external components.
4) The recording amplifier uses constant-current BLT drive that handles load variations (i.e. head imped ance)well, and gives stable recording characteris tics. A single circuit is provided for two-head VCR use.
5) Built-in recording level AGC means adjustment of FM recording current is not necessary.
6) Head switches for two-channel PRE / REC system provided.
7) Operates off a single 5V power supply, with low power dissipation.