Texas Instruments SN54AS821A

these 10-bit flip-flops feature 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. they are particularly suitable for implementing wider buffer registers i/o ports bidirectional bus drivers with parity and working registers. the ten flip-flops are edge-triggered d-type flip-flops. on the positive transition of the clock (clk) input the q outputs are true to the data (d) input. a buffered output-enable () input can be used to place the ten outputs in either a normal logic state (high or low logic levels) or a high- impedance state. in the high-impedance state the outputs neither load nor drive the bus lines significantly. the high-impedance state and increased drive provide the capability to drive bus lines without interface or pullup components. view all in datasheet