74HC244; 74HCT244
Philips Semiconductors
Octal buffer/line driver; 3-state
Table 9:
Dynamic characteristics 74HC244 …continued
GND = 0 V; tr = tf = 6 ns; CL = 50 pF unless otherwise specified; for test circuit see Figure 8.
Symbol Parameter
Conditions
Min
Typ
Max
Unit
Tamb = −40 °C to +125 °C
tPHL
tPLH
,
propagation delay nAn to nYn see Figure 6
VCC = 2.0 V
VCC = 4.5 V
VCC = 6.0 V
-
-
-
-
-
-
165
33
ns
ns
ns
28
tPZH
tPZL
,
,
3-state output enable time
nOE to nYn
see Figure 7
VCC = 2.0 V
VCC = 4.5 V
VCC = 6.0 V
see Figure 7
VCC = 2.0 V
VCC = 4.5 V
VCC = 6.0 V
see Figure 6
VCC = 2.0 V
VCC = 4.5 V
VCC = 6.0 V
-
-
-
-
-
-
225
45
ns
ns
ns
38
tPHZ
tPLZ
3-state output disable time
nOE to nYn
-
-
-
-
-
-
225
45
ns
ns
ns
38
tTHL
,
output transition time
tTLH
-
-
-
-
-
-
90
18
15
ns
ns
ns
[1] CPD is used to determine the dynamic power dissipation (PD in µW):
PD = CPD × VCC2 × fi × N + ∑(CL × VCC2 × fo) where:
fi = input frequency in MHz;
fo = output frequency in MHz;
CL = output load capacitance in pF;
VCC = supply voltage in V;
N = number of inputs switching;
∑(CL × VCC2 × fo) = sum of outputs.
Table 10: Dynamic characteristics type 74HCT244
GND = 0 V; tr = tf = 6 ns; CL = 50 pF unless otherwise specified; for test circuit see Figure 8.
Symbol Parameter
Conditions
Min
Typ
Max
Unit
Tamb = 25 °C
tPHL
tPLH
,
propagation delay nAn to nYn see Figure 6
VCC = 4.5 V
-
-
-
13
11
15
22
-
ns
ns
ns
VCC = 5 V; CL = 15 pF
tPZH
tPZL
,
,
3-state output enable time
nOE to nYn
VCC = 4.5 V; see Figure 7
VCC = 4.5 V; see Figure 7
VCC = 4.5 V; see Figure 6
VI = GND to (VCC − 1.5 V)
30
tPHZ
tPLZ
3-state output disable time
nOE to nYn
-
-
-
15
5
25
12
-
ns
ns
pF
tTHL
,
output transition time
tTLH
[1]
CPD
power dissipation
capacitance
35
74HC_HCT244_3
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
Product data sheet
Rev. 03 — 22 December 2005
11 of 22
NXP [ NXP ]
