Inverting buffer with 3-state outputs — the 74AHCT540 in 20-TSSOP
The Texas Instruments SN74AHCT540PW is an 8-bit inverting buffer with 3-state outputs from the 74AHCT logic family. It takes a single 4.5V to 5.5V supply rail and delivers 8 mA source and 8 mA sink per output. The inverting path means a logic-high input produces a logic-low output and vice versa — this is the key functional distinction from a non-inverting buffer like the 74AHCT541. The 3-state outputs let you disconnect the bus by pulling the output-enable pin high, which is standard for shared data lines.
-40°C to 125°C — industrial and automotive cabin use
The SN74AHCT540PW is rated over the full -40°C to 125°C ambient temperature range, which covers industrial motor drives, outdoor telecom cabinets, and automotive cabin electronics. That is a wider span than the 0°C to 70°C commercial-grade parts like the SN74LS645-1N, and it also exceeds the -40°C to 85°C range of the SN74ABT2245DW and SN74LVTH16245ADGVR. If your BOM calls for a 5V inverting buffer that must hold timing across a hot engine bay or a factory floor, this temperature grade is the deciding spec.
Active lifecycle — no LTB risk for new designs
The SN74AHCT540PW carries an Active product status with ROHS3 compliance. For a procurement desk qualifying a production BOM, this means you can design it in today without scheduling a future respin for obsolescence. The 20-TSSOP footprint is a standard 4.40mm-wide body, shared across the 74AHCT540 family, so a shift to the non-inverting variant or a different supply voltage tier keeps the same board layout.