These octal buffers and line drivers are designed to have the performance of the ?HCT240 devices and a pinout with inputs and outputs on opposite sides of the package. This arrangement greatly facilitates printed circuit board layout. The 3-state control gate is a 2-input NOR. If either output-enable (OE1 or OE2) input is high, all eight outputs are in the high-impedance state. The ?HCT540 devices provide inverted data at the outputs. To ensure the high-impedance state during power up or power down, OE should be tied to VCC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the

? Package Options Include: ? Plastic Small-Outline (D, NS, PS) ? Shrink Small-Outline (DB) ? Ceramic Flat (W) ? Ceramic Chip Carriers (FK) ? Standard Plastic (N) ? Ceramic (J) ? Also Available as Dual 2-Input Positive-NAND Gate in Small-Outline (PS) Package ? Inputs Are TTL Compliant; VIH = 2 V and VIL = 0.8 V ? Inputs Can Accept 3.3-V or 2.5-V Logic Inputs ? SN5400, SN54LS00, and SN54S00 are Characterized For Operation Over the Full Military Temperature Range of ?55?C to 125?C

n These bus buffers feature three-state outputs that, when enabled, have the low impedance characteristics of a TTL output with additional drive capability at high logic levels to permit driving heavily loaded bus lines without external pullup resistors. When disabled, both output transistors are turned off, presenting a high-impedance state to the bus so the output will act neither as a significant load nor as a driver. The ?125 and ?LS125A devices? outputs are disabled when G is high. The ?126 and ?LS126A devices? outputs are disabled when G is lo