Pin Descriptions
Pin Names
D0–D7
LE
OE
O0–O7
Description
Data Inputs
Latch Enable Input
Output Enable Input
3-STATE Outputs
Truth Table
Inputs
Outputs
LE
OE
Dn
On
X
H
X
Z
H
L
L
L
H
L
H
H
L
L
X
O0
H HIGH Voltage Level
L LOW Voltage Level
Z High Impedance
X Immaterial
O0 Previous O0 before HIGH-to-LOW transition of Latch Enable
Functional Description
The VHC373 contains eight D-type latches with 3-STATE
standard outputs. When the Latch Enable (LE) input is
HIGH, data on the Dn inputs enters the latches. In this con-
dition the latches are transparent, i.e., a latch output will
change state each time its D input changes. When LE is
LOW, the latches store the information that was present on
the D inputs a setup time preceding the HIGH-to-LOW tran-
sition of LE. The 3-STATE standard outputs are controlled
by the Output Enable (OE) input. When OE is LOW, the
standard outputs are in the 2-state mode. When OE is
HIGH, the standard outputs are in the high impedance
mode but this does not interfere with entering new data into
the latches.
Logic Diagram
Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.
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