SN74AC240DWR
八路缓冲器/驱动器,具有三态输出 OCTAL BUFFERS/DRIVERS WITH 3-STATE OUTPUTS
These octal buffers and line drivers are designed specifically to improve the performance and density of 3-state memory address drivers, clock drivers, and bus-oriented receivers and transmitters.
The AC240 devices are organized as two 4-bit buffers/drivers with separate output-enable OE\ inputs. When OE\ is low, the device passes inverted data from the A inputs to the Y outputs. When OE\ is high, the outputs are in the high-impedance state.
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 driver.