The BU34381 is a 4-bit microcomputer designed for CD-DA players, and has a wide array of internal I / O components, including an 8-bit, 8-channel AD converter, pulse width counter (PWC), two serial I / O, and an LCD controller / driver capable of displaying up to 80 segments. All LCD segments are programmable for CMOS output. These I / O components allow for multifunction applications with a low number of pins.

Features
1) High speed operations and low voltage. (VDD= 2.7 ~ 5.5V at 4.4MHz)
2) Internal 8-bit, 8-channel AD converter.
3) Internal pulse width counter.
4) Two internal serial input / outputs.
5) Internal 20-segment, 4-common LCD controller / driver. (usable with 3 commons)
6) All segments output by the LCD controller / driver are programmable for CMOS output.

Applications
    Portable CD-DA players, portable CD stereos