74HC244_05 Datasheet, PDF (12/22 Pages) NXP Semiconductors – Octal buffer/line driver; 3-state

Philips Semiconductors
74HC244; 74HCT244
Octal buffer/line driver; 3-state
Table 10: Dynamic characteristics type 74HCT244 …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
Conditions
Min
Typ
T_amb = −40 °C to +85 °C
t_PHL,
t_PLH
propagation delay nAn to nYn V_CC = 4.5 V; see Figure 6
-
-
t_PZH,
t_PZL
3-state output enable time
nOE to nYn
t_PHZ,
t_PLZ
3-state output disable time
nOE to nYn
t_THL,
t_TLH
output transition time
T_amb = −40 °C to +125 °C
V_CC = 4.5 V; see Figure 7
V_CC = 4.5 V; see Figure 7
V_CC = 4.5 V; see Figure 6
-
-
-
-
-
-
t_PHL,
t_PLH
propagation delay nAn to nYn V_CC = 4.5 V; see Figure 6
-
-
t_PZH,
t_PZL
3-state output enable time
nOE to nYn
V_CC = 4.5 V; see Figure 7
-
-
t_PHZ,
t_PLZ
3-state output disable time
nOE to nYn
V_CC = 4.5 V; see Figure 7
-
-
t_THL,
t_TLH
output transition time
V_CC = 4.5 V; see Figure 6
-
-
[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.
12. Waveforms
Max
Unit
28
ns
38
ns
31
ns
15
ns
33
ns
45
ns
38
ns
18
ns
74HC_HCT244_3
Product data sheet
V_I
nAn input
GND
V_OH
nYn output
V_OL
V_M
t _PHL
90 %
V_M
10 %
t _THL
V_M
t _PLH
V_M
t _TLH
001aae013
Fig 6.
Measurement points are given in Table 11.
V_OL and V_OH are typical voltage output drop that occur with the output load.
Propagation delay input (1An, 2An) to output (1Yn, 2Yn) and transition time output
(nYn)
Rev. 03 — 22 December 2005
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
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