Datasheet

9397 750 14502 © Koninklijke Philips Electronics N.V. 2005. All rights reserved.
Product data sheet Rev. 03 — 31 January 2005 12 of 22
Philips Semiconductors
74HC245; 74HCT245
Octal bus tranceiver; 3-state
[1] C
PD
is used to determine the dynamic power dissipation (P
D
in µW):
P
D
=C
PD
× V
CC
2
× f
i
× N+∑ (C
L
× V
CC
2
× 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
CC
2
× f
o
) = sum of outputs.
Table 10: Dynamic characteristics type 74HCT245
GND = 0 V; test circuit see Figure 7.
Symbol Parameter Conditions Min Typ Max Unit
T
amb
= 25 °C
t
PHL
, t
PLH
propagation delay An to Bn or Bn
to An
see Figure 5
V
CC
= 4.5 V - 12 22 ns
V
CC
= 5.0 V; C
L
=15pF - 10 - ns
t
PZH
, t
PZL
3-state output enable time OE to
An or
OE to Bn
V
CC
= 4.5 V; see Figure 6 - 1630ns
t
PHZ
, t
PLZ
3-state output disable time OE to
An or
OE to Bn
V
CC
= 4.5 V; see Figure 6 - 1630ns
t
THL
, t
TLH
output transition time V
CC
= 4.5 V; see Figure 5 - 5 12 ns
C
PD
power dissipation capacitance
per transceiver
V
I
= GND to V
CC
− 1.5 V
[1]
-30-pF
T
amb
= −40 °C to +85 °C
t
PHL
, t
PLH
propagation delay An to Bn or Bn
to An
V
CC
= 4.5 V; see Figure 5 --28ns
t
PZH
, t
PZL
3-state output enable time OE to
An or
OE to Bn
V
CC
= 4.5 V; see Figure 6 --38ns
t
PHZ
, t
PLZ
3-state output disable time OE to
An or
OE to Bn
V
CC
= 4.5 V; see Figure 6 --38ns
t
THL
, t
TLH
output transition time V
CC
= 4.5 V; see Figure 5 --15ns
T
amb
= −40 °C to +125 °C
t
PHL
, t
PLH
propagation delay An to Bn or Bn
to An
V
CC
= 4.5 V; see Figure 5 --33ns
t
PZH
, t
PZL
3-state output enable time OE to
An or
OE to Bn
V
CC
= 4.5 V; see Figure 6 --45ns
t
PHZ
, t
PLZ
3-state output disable time OE to
An or
OE to Bn
V
CC
= 4.5 V; see Figure 6 --45ns
t
THL
, t
TLH
output transition time V
CC
= 4.5 V; see Figure 5 --18ns