Philips Semiconductors
74HC244; 74HCT244
Octal buffer/line driver; 3-state
Table 9:
Dynamic characteristics 74HC244
…continued
GND = 0 V; t
r
= t
f
= 6 ns; C
L
= 50 pF unless otherwise specified; for test circuit see
Figure 8.
Symbol Parameter
T
amb
=
−40 °C
to +125
°C
t
PHL
,
t
PLH
propagation delay nAn to nYn see
V
CC
= 2.0 V
V
CC
= 4.5 V
V
CC
= 6.0 V
t
PZH
,
t
PZL
3-state output enable time
nOE to nYn
see
V
CC
= 2.0 V
V
CC
= 4.5 V
V
CC
= 6.0 V
t
PHZ
,
t
PLZ
3-state output disable time
nOE to nYn
see
V
CC
= 2.0 V
V
CC
= 4.5 V
V
CC
= 6.0 V
t
THL
,
t
TLH
output transition time
see
V
CC
= 2.0 V
V
CC
= 4.5 V
V
CC
= 6.0 V
[1]
C
PD
is used to determine the dynamic power dissipation (P
D
in
µW):
P
D
= C
PD
×
V
CC2
×
f
i
×
N +
∑(C
L
×
V
CC2
×
f
o
) where:
f
i
= input frequency in MHz;
f
o
= output frequency in MHz;
C
L
= output load capacitance in pF;
V
CC
= supply voltage in V;
N = number of inputs switching;
∑(C
L
×
V
CC2
×
f
o
) = sum of outputs.
Conditions
Min
Typ
Max
Unit
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
165
33
28
225
45
38
225
45
38
90
18
15
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Table 10: Dynamic characteristics type 74HCT244
GND = 0 V; t
r
= t
f
= 6 ns; C
L
= 50 pF unless otherwise specified; for test circuit see
Symbol Parameter
T
amb
= 25
°C
t
PHL
,
t
PLH
propagation delay nAn to nYn see
V
CC
= 4.5 V
V
CC
= 5 V; C
L
= 15 pF
t
PZH
,
t
PZL
t
PHZ
,
t
PLZ
t
THL
,
t
TLH
C
PD
3-state output enable time
nOE to nYn
3-state output disable time
nOE to nYn
output transition time
power dissipation
capacitance
V
CC
= 4.5 V; see
V
CC
= 4.5 V; see
V
CC
= 4.5 V; see
V
I
= GND to (V
CC
−
1.5 V)
Conditions
Min
Typ
Max
Unit
-
-
-
-
-
-
13
11
15
15
5
35
22
-
30
25
12
-
ns
ns
ns
ns
ns
pF
74HC_HCT244_3
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
Product data sheet
Rev. 03 — 22 December 2005
11 of 22
PHILIPS [ NXP SEMICONDUCTORS ]
