Datasheet

December 1990 9
Philips Semiconductors Product specification
Presettable synchronous 4-bit binary
counter; asynchronous reset
74HC/HCT161
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
MR 0.95
CP 1.10
CEP 0.25
D
n
0.25
CET 0.75
PE 0.30
SYMBOL PARAMETER
T
amb
(°C)
UNIT
TEST CONDITIONS
74HCT
V
CC
(V)
WAVEFORMS
+25 −40 to +85 −40 to +125
min. typ. max. min. max. min. max.
t
PHL
/ t
PLH
propagation delay
CP to Q
n
23 43 54 65 ns 4.5 Fig.8
t
PHL
/ t
PLH
propagation delay
CP to TC
28 48 60 72 ns 4.5 Fig.8
t
PHL
propagation delay
MR to Q
n
29 46 58 69 ns 4.5 Fig.9
t
PHL
propagation delay
MR to TC
30 51 64 77 ns 4.5 Fig.9
t
PHL
/ t
PLH
propagation delay
CET to TC
17 35 44 53 ns 4.5 Fig.10
t
THL
/ t
TLH
output transition time 7 15 19 22 ns 4.5 Figs 8 and 10
t
W
clock pulse width
HIGH or LOW
16 7 20 24 ns 4.5 Fig.8
t
W
master reset pulse
width; LOW
20 10 25 30 ns 4.5 Fig.9
t
rem
removal time
MR to CP
20 6 25 30 ns 4.5 Fig.9