MM54HC620/MM74HC620 Inverting
Octal TRI-STATEé Transceiver
MM54HC623/MM74HC623 True
Octal TRI-STATE Transceiver
General Description
These TRI-STATE bi-directional buffers utilize advanced silicon-
gate CMOS technology and are intended for two-way
asynchronous communication between data buses. They
have high drive current outputs which enable high speed
operation even when driving large bus capacitances. These
circuits possess the low power consumption and high noise
immunity usually associated with CMOS circuitry, yet have
speeds comparable to low power Schottky TTL circuits.
These devices allow data transmission from the A bus to
the B bus or from the B bus to the A bus depending on the
logic levels at the enable inputs. Both buses can be isolated
from each other with proper logic levels at the enable inputs.
When GAB is taken high and GBA is taken low, these
devices store the states presently appearing at the data inputs.
The 8-bit codes appearing on the two sets of buses
will be indentical for the 623 option or complimentary for the
620 option.
These devices can drive up to 15 LS-TTL loads. All inputs
are protected from damage due to static discharge by diodes
to VCC and ground.