Datasheet

December 1990 7
Philips Semiconductors Product specification
Dual 4-bit synchronous binary counter 74HC/HCT4520
AC WAVEFORMS
PACKAGE OUTLINES
See “74HC/HCT/HCU/HCMOS Logic Package Outlines” .
Fig.7 Waveforms showing removal time for nMR; minimum nCP
0
, nCP
1
, nMR pulse widths and maximum clock
pulse frequency.
Conditions:
n
CP
1
= HIGH while nCP
0
is triggered on a LOW-to-HIGH transition; t
W
and t
rem
also apply when nCP
0
= LOW and nCP
1
is triggered on a
HIGH-to-LOW transition.
(1) HC : V
M
= 50%; V
I
= GND to V
CC.
HCT: V
M
= 1.3 V; V
I
= GND to 3 V.
Fig.8 Waveforms showing set-up times for nCP
0
to nCP
1
and nCP
1
to nCP
0
, propagation delays and output
transition times.
(1) HC : V
M
= 50%; V
I
= GND to V
CC.
HCT: V
M
= 1.3 V; V
I
= GND to 3 V.
Fig.9 Waveforms showing propagation delay from nMR to nQ
n
output.
(1) HC : V
M
= 50%; V
I
= GND to V
CC.
HCT: V
M
= 1.3 V; V
I
= GND to 3 V.