SN54AC574, SN74AC574
OCTAL D-TYPE EDGE-TRIGGERED FLIP-FLOPS
WITH 3-STATE OUTPUTS

SCAS541B - OCTOBER 1995 - REVISED JUNE 1996

features

• 3-State Outputs Drive Bus Lines Directly
• EPIC^TM (Enhanced-Performance Implanted CMOS) 1-m Process
• Package Options Include Plastic Small-Outline (DW) Shrink Small-Outline (DB), and Thin Shrink Small-Outline (PW) Packages, Ceramic Chip Carriers (FK) and Flatpacks (W), and Standard Plastic (N) and Ceramic (J) DIP Packages

  EPIC is a trademark of Texas Instruments Incorporated.

description

These 8-bit flip-flops feature 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. The devices are particularly suitable for implementing buffer registers, I/O ports, bidirectional bus drivers, and working registers.

The eight flip-flops of the ´AC574 are D-type edge-triggered flip-flops. On the positive transition of the clock (CLK) input, the Q outputs are set to the logic levels set up at the data (D) inputs.

A buffered output-enable () input can be used to place the eight outputs in either a normal logic state (high or low logic levels) or the high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly. The high-impedance state and the increased drive provide the capability to drive bus lines in a bus-organized system without need for interface or pullup components.

does not affect internal operations of the flip-flop. Old data can be retained or new data can be entered while the outputs are in the high-impedance state.

The SN54AC574 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74AC574 is characterized for operation from -40°C to 85°C.