74HCT259BQ-Q100 PCB Symbol, Footprint & ECAD Model

The 74HC259-Q100; 74HCT259-Q100 are high-speed Si-gate CMOS devices and are pin compatible with Low-power Schottky TTL (LSTTL). They are specified in compliance with JEDEC standard No. 7A.

The 74HC259-Q100; 74HCT259-Q100 are high-speed 8-bit addressable latches designed for general-purpose storage applications in digital systems. They are multifunctional devices capable of storing single-line data in eight addressable latches and providing a 3-to-8 decoder and multiplexer function with active HIGH outputs (Q0 to Q7). They also incorporate an active LOW common reset (MR) for resetting all latches as well as an active LOW enable input (LE).

The 74HC259-Q100; 74HCT259-Q100 has four modes of operation:

• Addressable latch mode, in this mode data on the data line (D) is written into the addressed latch. The addressed latch follows the data input with all non-addressed latches remaining in their previous states.
• Memory mode, in this mode all latches remain in their previous states and are unaffected by the data or address inputs.
• Demultiplexing mode (or 3-to-8 decoding), in this mode the addressed output follows the state of the data input (D) with all other outputs in the LOW state.
• Reset mode, in this mode all outputs are LOW and unaffected by the address inputs (A0 to A2) and data input (D).

When operating the 74HC259-Q100; 74HCT259-Q100 as an address latch, changing more than one address bit could impose a transient wrong address. Therefore, this should only be done while in the Memory mode.

This product has been qualified to the Automotive Electronics Council (AEC) standard Q100 (Grade 1) and is suitable for use in automotive applications.