Datasheet

December 1990 2
Philips Semiconductors Product specification
Octal buffer/line driver; 3-state 74HC/HCT244
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.
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 1
OE 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.
QUICK REFERENCE DATA
GND = 0 V; T
amb
=25°C; t
r
=t
f
= 6 ns
Notes
1. C
PD
is used to determine the dynamic power dissipation (P
D
in µW):
P
D
=C
PD
× V
CC
2
× f
i
+∑ (C
L
× V
CC
2
× f
o
) where:
f
i
= input frequency in MHz
f
o
= output frequency in MHz
∑ (C
L
× V
CC
2
× 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” .
SYMBOL PARAMETER CONDITIONS
TYPICAL
UNIT
HC HCT
t
PHL
/ t
PLH
propagation delay
1A
n
to 1Y
n
;
2A
n
to 2Y
n
C
L
= 15 pF; V
CC
=5V 9 11 ns
C
I
input capacitance 3.5 3.5 pF
C
PD
power dissipation capacitance per buffer notes 1 and 2 35 35 pF