MC74VHC259
8-Bit Addressable Latch/1-of-8 Decoder CMOS Logic Level Shifter
with LSTTL−Compatible Inputs
The MC74VHC259 ...
MC74VHC259
8-Bit Addressable Latch/1-of-8 Decoder
CMOS Logic Level Shifter
with LSTTL−Compatible Inputs
The MC74VHC259 is an 8−bit Addressable Latch fabricated with silicon gate
CMOS technology. It achieves high speed operation similar to equivalent Bipolar Schottky TTL devices while maintaining
CMOS low power dissipation.
The VHC259 is designed for general purpose storage applications in digital systems. The device has four modes of operation as shown in the mode selection table.. In the addressable latch mode, the data on Data In is written into the addressed latch. The addressed latch follows the data input with all non−addressed latches remaining in their previous states. In the memory mode, all latches remain in their previous state and are unaffected by the Data or Address inputs. In the one−of−eight decoding or demultiplexing mode, the addressed output follows the state of Data In with all other outputs in the LOW state. In the Reset mode, all outputs are LOW and unaffected by the address and data inputs. When operating the VHC259 as an addressable latch, changing more than one bit of the address could impose a transient wrong address. Therefore, this should only be done while in the memory mode.
The MC74VHC259 input structure provides protection when
voltages up to 7 V are applied, regardless of the supply
voltage. This allows the MC74VHC259 to be used to interface 5 V circuits to 3 V circuits.
High Speed: tPD = 7.6 ns (Typ) at VCC = 5 V Low Power Dissipation: IC...