The BU4028B is a decoder which converts BCD signals to decimal signals.
Of the ten outputs Q0 to Q9, those corresponding to the A to D input codes are set to “H”, and the others are all set to “L”.
If inputs A to C are used and input D is used as disabled input, the BU4028B can also be used as a 1-of-8 decoder.

•Features
1) Low power dissipation.
2) Wide range of operating power supply voltages.
3) High input impedance.
4) High fan-out.
5) Direct drive of 2 L-TTL inputs and 1LS-TTL input.