Philips Semiconductors
Product specification
Octal buffer/line driver; 3-state
FEATURES
•
Output capability: bus driver
•
I
CC
category: MSI
GENERAL DESCRIPTION
The 74HC/HCT244 are high-speed Si-gate CMOS devices
and are pin compatible with low power Schottky TTL
(LSTTL). They are specified in compliance with JEDEC
standard no. 7A.
QUICK REFERENCE DATA
GND = 0 V; T
amb
= 25
°C;
t
r
= t
f
= 6 ns
74HC/HCT244
The 74HC/HCT244 are octal non-inverting buffer/line
drivers with 3-state outputs. The 3-state outputs are
controlled by the output enable inputs 1OE and 2OE.
A HIGH on nOE causes the outputs to assume a high
impedance OFF-state. The “244” is identical to the “240”
but has non-inverting outputs.
TYPICAL
SYMBOL
t
PHL
/ t
PLH
PARAMETER
propagation delay
1A
n
to 1Y
n
;
2A
n
to 2Y
n
input capacitance
power dissipation capacitance per buffer
notes 1 and 2
CONDITIONS
HC
C
L
= 15 pF; V
CC
= 5 V
9
HCT
11
ns
UNIT
C
I
C
PD
Notes
3.5
35
3.5
35
pF
pF
1. C
PD
is used to determine the dynamic power dissipation (P
D
in
µW):
P
D
= C
PD
×
V
CC2
×
f
i
+ ∑
(C
L
×
V
CC2
×
f
o
) where:
f
i
= input frequency in MHz
f
o
= output frequency in MHz
∑
(C
L
×
V
CC2
×
f
o
) = sum of outputs
C
L
= output load capacitance in pF
V
CC
= supply voltage in V
2. For HC the condition is V
I
= GND to V
CC
For HCT the condition is V
I
= GND to V
CC
−
1.5 V
ORDERING INFORMATION
See
“74HC/HCT/HCU/HCMOS Logic Package Information”.
December 1990
2
PHILIPS [ NXP SEMICONDUCTORS ]
