1. General description

The 74HC259; 74HCT259 is an 8-bit addressable latch. The device features four modes of

operation. In the addressable latch mode, data on the D input is written into the latch addressed

by the inputs A0 to A3. The addressed latch will follow the data input, non-addressed latches

will retain their previous states. In memory mode, all latches retain their previous states and are

unaffected by the data or address inputs. In the 3-to-8 decoding or demultiplexing mode, the

addressed output follows the D input and all other outputs are LOW. In the reset mode, all outputs

are forced LOW and unaffected by the data or address inputs. Inputs include clamp diodes. This

enables the use of current limiting resistors to interface inputs to voltages in excess of VCC.

2. Features and benefits

? Wide supply voltage range from 2.0 V to 6.0 V

? Latch-up performance exceeds 100 mA per JESD 78 Class II Level B

? Complies with JEDEC standards:

? JESD8C (2.7 V to 3.6 V)

? JESD7A (2.0 V to 6.0 V)

? Combined demultiplexer and 8-bit latch

? Serial-to-parallel capability

? Output from each storage bit available

? Random (addressable) data entry

? Easily expandable

? Common reset input

? Useful as a 3-to-8 active HIGH decoder

? Input levels:

? For 74HC259: CMOS level

? For 74HCT259: TTL level

? ESD protection:

? HBM: ANSI/ESDA/Jedec JS-001 Class 2 exceeds 2000 V

? CDM: ANSI/ESDA/Jedec JS-002 Class C3 exceeds 1000 V

? Multiple package options

? Specified from -40 °C to +85 °C and from -40 °C to +125 °C