Datasheet

September 1993 8
Philips Semiconductors Product specification
Dual retriggerable precision monostable
multivibrator
74HC/HCT4538
DC CHARACTERISTICS FOR 74HCT
For the DC characteristics see “74HC/HCT/HCU/HCMOS Logic Family Specifications” .
Output capability: standard
I
CC
category: MSI
Note to HCT types
The value of additional quiescent supply current (∆I
CC
) for a unit load of 1 is given in the family specifications.
To determine ∆I
CC
per input, multiply this value by the unit load coefficient shown in the table below.
AC CHARACTERISTICS FOR 74HCT
GND = 0 V; t
r
= t
f
= 6 ns; C
L
= 50 pF
INPUT UNIT LOAD COEFFICIENT
n
A
0
,nA
1
nR
D
0.50
0.65
SYMBOL PARAMETER
T
amb
(°C)
UNIT
TEST CONDITIONS
74HCT
V
CC
(V)
OTHER
+25 −40 to +85 −40 to +125
min. typ. max. min. max. min. max.
t
PLH
propagation delay
nA
0
,nA
1
to nQ
35 60 75 90 ns 4.5 Fig.8
t
PHL
propagation delay
nA
0
,nA
1
to nQ
35 60 75 90 ns 4.5 Fig.8
t
PHL
propagation delay
nR
D
to nQ
35 60 75 90 ns 4.5 Fig.8
t
PLH
propagation delay
nR
D
to nQ
35 60 75 90 ns 4.5 Fig.8
t
THL
/ t
TLH
output transition time 7 15 19 21 ns 4.5 Fig.8
t
W
nA
0
pulse width
LOW
20 11 25 30 ns 4.5 Fig.8
t
W
nA
1
pulse width
HIGH
16 5 20 24 ns 4.5 Fig.8
t
W
nR
D
pulse width
LOW
20 11 25 30 ns 4.5 Fig.8
t
W
nQ, nQ pulse width
HIGH or LOW
0.63 0.70 0.77 0.602 0.798 0.595 0.805 ms 5.0 Fig.8; R
t
= 10 kΩ;
C
t
= 0.1 µF
t
rem
removal time
R
D
to nA
0
, nA1
7 2 9 11 ns 4.5 Fig.8
t
rt
retrigger time
nA
0
,nA
1
− 80+X −−ns 4.5 Fig.8
X=C
EXT
/
(4.5 × V
CC
)
R
EXT
external timing
resistor
2 1000 kΩ 5.0
C
EXT
external timing
capacitor
no limits
pF 5.0