March 1988 5
Philips Semiconductors Product specification
Octal bus transceiver; 3-state; inverting 74HC/HCT640
DC CHARACTERISTICS FOR 74HCT
For the DC characteristics see
“74HC/HCT/HCU/HCMOS Logic Family Specifications”
.
Output capability: bus driver
I
CC
category: MSI
Note to HCT types
The value of additional quiescent supply current (∆I
CC
) for a unit load of 1 is given in the family specifications.
To determine ∆I
CC
per input, multiply this value by the unit load coefficient shown in the table below.
AC CHARACTERISTICS FOR 74HCT
GND = 0 V; t
r
=t
f
= 6 ns; C
L
=50pF
INPUT UNIT LOAD COEFFICIENT
A
n
B
n
OE
DIR
1.50
1.50
1.50
0.90
SYMBOL PARAMETER
T
amb
(°C)
UNIT
TEST CONDITIONS
74HCT
V
CC
(V)
WAVEFORMS+25 −40 to +85 −40 to +125
min. typ. max. min. max. min. max.
t
PHL
/ t
PLH
propagation delay
A
n
to B
n
;
B
n
to A
n
11 22 28 33 ns 4.5 Fig.5
t
PZH
/ t
PZL
3-state output enable time
OE, DIR to A
n
;
OE, DIR to B
n
18 30 38 45 ns 4.5 Fig.6
t
PHZ
/ t
PLZ
3-state output disable time
OE, DIR to A
n
;
OE, DIR to B
n
19 30 38 45 ns 4.5 Fig.6
t
THL
/ t
TLH
output transition time 5 12 15 18 ns 4.5 Fig.5
