74vcx16721 Fairchild Semiconductor, 74vcx16721 Datasheet - Page 2

• Manufacturer Part Number: 74vcx16721
• Description: 74vcx16721 Low Voltage 20-bit D-type Flip-flops With 3.6v Tolerant Inputs And Outputs
• Manufacturer: Fairchild Semiconductor

www.fairchildsemi.com
Connection Diagram
Logic Diagram
2
Truth Table
H
L
X
Z

O
Functional Description
The VCX16721 contains twenty D-type flip-flops with
3-STATE standard outputs. The twenty flip-flops will store
the state of their individual D-type inputs that meet the
setup and hold time requirements on the LOW-HIGH Clock
(CLK) transition, when the Clock-Enable (CE) is LOW. The
3-STATE standard outputs are controlled by the Output-
Enable (OE). When OE is HIGH, the standard outputs are
in high impedance mode but this does not interfere with
entering new data into the flip-flops.
0
LOW Voltage Level
High Impedance
L or H
HIGH Voltage Level
Immaterial (HIGH or LOW, inputs may not float)
CLK
Previous O
LOW-to-HIGH transition


X
X
0
before LOW-to-HIGH transition of Clock
CE
H
X
L
L
L
OE
H
L
L
L
L
D
0
–D
X
X
H
X
L
19
O
0
O
O
–O
H
Z
L
0
0
19