m74hct640 STMicroelectronics, m74hct640 Datasheet - Page 2

• Manufacturer Part Number: m74hct640
• Description: Ic Transcvr Tri-st 8bit 20dip
• Manufacturer: STMicroelectronics

M74HCT640
INPUT AND OUTPUT EQUIVALENT CIRCUIT
TRUTH TABLE
X : Don’t Care
Z : High Impedance
LOGIC DIAGRAM
This logic diagram has not be used to estimate propagation delays
2/11
G
H
L
L
INPUTS
DIR
H
X
L
OUTPUT
A BUS
INPUT
Z
PIN DESCRIPTION
2, 3, 4, 5, 6,
18, 17, 16,
15, 14, 13,
FUNCTION
PIN No
7, 8, 9
12, 11
19
10
20
1
OUTPUT
SYMBOL
B BUS
A1 to A8
B1 to B8
INPUT
GND
V
DIR
Z
G
CC
Directional Control
Data Inputs/Outputs
Data Inputs/Outputs
Output Enable Input
Ground (0V)
Positive Supply Voltage
NAME AND FUNCTION
OUTPUT
B = A
A = B
Z