74HC393 Datasheet, PDF (2/7 Pages) NXP Semiconductors – Dual 4-bit binary ripple counter

Philips Semiconductors
Dual 4-bit binary ripple counter
Product specification
74HC/HCT393
FEATURES
• Two 4-bit binary counters with individual clocks
• Divide-by any binary module up to 28 in one package
• Two master resets to clear each 4-bit counter
individually
• Output capability: standard
• I_CC category: MSI
GENERAL DESCRIPTION
The 74HC/HCT393 are high-speed Si-gate CMOS devices
and are pin compatible with low power Schottky TTL
(LSTTL). They are specified in compliance with JEDEC
standard no. 7A.
The 74HC/HCT393 are 4-bit binary ripple counters with
separate clocks (1CP and 2 CP) and master reset (1MR
and 2MR) inputs to each counter. The operation of each
half of the “393” is the same as the “93” except no external
clock connections are required.
The counters are triggered by a HIGH-to-LOW transition of
the clock inputs. The counter outputs are internally
connected to provide clock inputs to succeeding stages.
The outputs of the ripple counter do not change
synchronously and should not be used for high-speed
address decoding.
The master resets are active-HIGH asynchronous inputs
to each 4-bit counter identified by the “1” and “2” in the pin
description.
A HIGH level on the nMR input overrides the clock and
sets the outputs LOW.
QUICK REFERENCE DATA
GND = 0 V; T_amb = 25 °C; t_r = t_f = 6 ns
SYMBOL
PARAMETER
CONDITIONS
t_PHL/ t_PLH
f_max
C_I
C_PD
propagation delay
nCP to nQ₀
nQ to nQ_n+1
nMR to nQ_n
maximum clock frequency
input capacitance
power dissipation capacitance per counter
C_L = 15 pF; V_CC = 5 V
notes 1 and 2
Notes
1. C_PD is used to determine the dynamic power dissipation (P_D in µW):
P_D = C_PD × V_CC2 × f_i + ∑ (C_L × V_CC2 × f_o) where:
f_i = input frequency in MHz
f_o = output frequency in MHz
∑ (C_L × V_CC2 × f_o) = sum of outputs
C_L = output load capacitance in pF
V_CC = supply voltage in V
2. For HC the condition is V_I = GND to V_CC
For HCT the condition is V_I = GND to V_CC − 1.5 V
ORDERING INFORMATION
See “74HC/HCT/HCU/HCMOS Logic Package Information”.
TYPICAL
HC HCT
UNIT
12
20
ns
5
6
ns
11
15
ns
99
53
MHz
3.5
3.5
pF
23
25
pF
December 1990
2