The SN74LS42N is a 4-line BCD to 10-line Decimal Decoder with eight inverters and ten 4-input NAND gates. The inverters are connected in pairs to make BCD input data available for decoding by the NAND gates. Full decoding of valid input logic ensures that all outputs remain off for all invalid input conditions. It feature inputs and outputs that are compatible for use with most TTL and other saturated low-level logic circuits. DC noise margins are typically 1V.

• High for invalid input conditions
• Diode-clamped inputs