December 1990
2
Philips Semiconductors
Product specication
Octal D-type ip-op; 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; Tamb =25 °C; tr =tf = 6 ns
Notes
1. CPD is used to determine the dynamic power dissipation (PD in W):
PD =CPD × VCC2 × fi +∑ (CL × VCC2 × fo) where:
fi = input frequency in MHz
fo = output frequency in MHz
∑ (CL × VCC2 × fo) = sum of outputs
CL = output load capacitance in pF
VCC = supply voltage in V
2. For HC the condition is VI = GND to VCC
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
tPHL/ tPLH
propagation delay CP to Qn
CL = 15 pF; VCC = 5 V
15
13
ns
fmax
maximum clock frequency
77
48
MHz
CI
input capacitance
3.5
pF
CPD
power dissipation capacitance per ip-op
notes 1 and 2
17
pF