



SCBS187F - JANUARY 1991 - REVISED JANUARY 1997
Please be aware that an important notice concerningavailability, standard warranty, and use in critical applications ofTexasInstruments semiconductor products and disclaimers theretoappears at the end of this data sheet.
EPIC-IIB is a trademark of Texas Instrumentsdescription
These 8-bit flip-flops with 3-state outputs are designedspecifically for driving highly capacitive or relativelylow-impedance loads. They are particularly suitable for implementingbuffer registers, I/O ports, bidirectional bus drivers, and workingregisters.
The eight flip-flops are edge-triggered D-type flip-flops. On thepositive transition of the clock (CLK), the Q\ outputs are set to thecomplement of the logic levels set up at the data (D) inputs.
A buffered output-enable (
) input can be used to place the eight outputs in eithera normal logic state (high or low logic levels) or a high-impedancestate. In the high-impedance state, the outputs neither load nordrive the bus lines significantly. The high-impedance state andincreased drive provide the capability to drive bus lines withoutneed for interface or pullup components.
does not affectthe internal operations of the flip-flop. Previously stored data canbe retained or new data can be entered while the outputs are in thehigh-impedance state.
To ensure the high-impedance state during power up or power down,
should be tiedto VCC through a pullup resistor; the minimum value of theresistor is determined by the current-sinking capability of thedriver.
The SN54ABT534 is characterized for operation over the fullmilitary temperature range of -55°C to 125°C. TheSN74ABT534A is characterized for operation from -40°C to85°C.
View more information about generic part numbers:SN74ABT534A
Go to the Engineering Design Center to locate information on other TI Semiconductor devices.



