What this part is and where it fits
The 54LS26DMQB is a NAND gate from the LS series of TTL logic, supplied in bulk packaging. It performs the standard NAND logic function — output low only when all inputs are high.

54LS26DMQB, NAND Gate, LS Series TTL, Bulk Package.
| Parameter | Value |
|---|---|
| Series | * |
| Package | Bulk |
The 54LS26DMQB is a NAND gate from the LS series of TTL logic, supplied in bulk packaging. It performs the standard NAND logic function — output low only when all inputs are high.
The 54LS26DMQB is the military-temperature-range version of the standard 74LS26, typically rated for -55°C to +125°C operation versus the 74LS26's commercial 0°C to 70°C range. The 54 prefix also implies tighter process control and wider supply tolerance, though both share the same LS TTL logic family and NAND function.