74HC640 Datasheet, PDF (3/6 Pages) NXP Semiconductors – Octal bus transceiver; 3-state; inverting

Philips Semiconductors
Octal bus transceiver; 3-state; inverting
PIN DESCRIPTION
PIN NO.
SYMBOL NAME AND FUNCTION
1
DIR
direction control
2, 3, 4, 5, 6, 7, 8, 9
10
A₀ to A₇ data inputs/outputs
GND
ground (0 V)
18, 17, 16, 15, 14, 13, 12, 11 B₀ to B₇ data inputs/outputs
19
OE
output enable input (active LOW)
20
V_CC
positive supply voltage
Product specification
74HC/HCT640
Fig.1 Pin configuration.
Fig.2 Logic symbol.
FUNCTION TABLE
inputs
OE DIR
L
L
L
H
H
X
inputs/outputs
A_n
A=B
inputs
Z
B_n
inputs
B=A
Z
Note
1. H = HIGH voltage level
L = LOW voltage level
X = don’t care
Z = high impedance OFF-state
Fig.3 IEC logic symbol.
March 1988
Fig.4 Functional diagram.
3