The Texas Instruments SN74LS365AN is a 74LS-series hex non-inverting buffer with 3-state outputs in a 16-pin DIP through-hole package. Each of the six buffer elements can source 2.6 mA and sink 24 mA, making it suitable for driving bus lines, LED indicators, or CMOS inputs on legacy 5V logic backplanes. The 3-state output control allows multiple devices to share a common data bus without contention.
Active lifecycle — no near-term obsolescence concern
It is ROHS3 compliant. This is a mature 74LS part that continues to serve legacy maintenance, repair, and low-volume production builds where 5V TTL-compatible logic is still required.
Output drive and bus interfacing
The 24 mA sink capability per output is the headline rating that matters for bus loading. It can drive up to ten standard 74LS loads (each at 0.4 mA input low current) with margin, or directly switch a small relay coil through a pull-up resistor. The 2.6 mA source current is lower — typical for 74LS totem-pole outputs — so when driving high-impedance CMOS inputs, a pull-up resistor to 5V is often added to improve noise margin and rise time. The 3-state enable control is active-low on this variant; verify the enable polarity against your bus controller's output enable signal.
Package and handling for the rework bench
The 16-pin DIP (0.300" body width) is a through-hole package that hand-solders easily and survives repeated rework without pad lift. No moisture sensitivity level applies to hermetic DIP packages — no bake required before assembly. The 0.100" pin pitch is standard for breadboard prototyping and legacy PCB layouts. When sourcing for a repair or retrofit, the DIP form factor means a direct drop-in replacement for any 16-pin DIP hex buffer in the same socket footprint.
