December 1990 2
Philips Semiconductors Product specification
Octal D-type flip-flop; positive
edge-trigger; 3-state
74HC/HCT374
FEATURES
• 3-state non-inverting outputs for bus oriented
applications
• 8-bit positive, edge-triggered register
• Common 3-state output enable input
• Independent register and 3-state buffer operation
• Output capability: bus driver
• ICC category: MSI
GENERAL DESCRIPTION
The 74HC/HCT374 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/HCT374 are octal D-type flip-flops featuring
separate D-type inputs for each flip-flop and 3-state
outputs for bus oriented applications. A clock (CP) and an
output enable (
OE) input are common to all flip-flops.
The 8 flip-flops will store the state of their individual
D-inputs that meet the set-up and hold times requirements
on the LOW-to-HIGH CP transition.
When OE is LOW, the contents of the 8 flip-flops are
available at the outputs. When OE is HIGH, the outputs go
to the high impedance OFF-state. Operation of the
OE input does not affect the state of the flip-flops.
The “374” is functionally identical to the “534”, but has
non-inverting outputs.
QUICK REFERENCE DATA
GND = 0 V; T
amb
=25°C; tr=tf= 6 ns
Notes
1. C
PD
is used to determine the dynamic power dissipation (PD in µW):
PD=CPD× V
CC
2
× fi+∑ (CL× V
CC
2
× fo) where:
fi= input frequency in MHz
fo= output frequency in MHz
∑ (CL× V
CC
2
× fo) = sum of outputs
CL= output load capacitance in pF
VCC= supply voltage in V
2. For HC the condition is VI= GND to V
CC
For HCT the condition is VI= GND to VCC− 1.5 V
ORDERING INFORMATION
See
“74HC/HCT/HCU/HCMOS Logic Package Information”
.
SYMBOL PARAMETER CONDITIONS
TYPICAL
UNIT
HC HCT
t
PHL
/ t
PLH
propagation delay CP to Q
n
CL= 15 pF; VCC= 5 V 15 13 ns
f
max
maximum clock frequency 77 48 MHz
C
I
input capacitance 3.5 3.5 pF
C
PD
power dissipation capacitance per flip-flop notes 1 and 2 17 17 pF