Eight-bit inverting line driver with 3-state control
The Texas Instruments SN74HC540N is an 8-bit inverting buffer with 3-state outputs, built on the 74HC logic family. It takes eight input signals and delivers the inverted logic levels to the outputs, with a common output-enable (OE) pin that puts all outputs into a high-impedance state when pulled high. This makes it a straightforward choice for driving a data bus where the bus direction is fixed but bus contention must be avoided — typical in memory-interface, address-latch, or general-purpose line-driver roles on a 5V or 3.3V backplane. The wide supply range from 2V to 6V covers both TTL-compatible 5V rails and lower-voltage logic systems, and the industrial temperature range (-40°C to 85°C) suits factory-floor control cabinets, outdoor telecom gear, and similar environments where the board sees ambient swings.
What the 7.8 mA output drive means for your bus
The SN74HC540N sources and sinks 7.8 mA per output at 5V. That is enough to drive one or two standard 74HC or 74HCT inputs, or a low-power LED indicator.