Philips Semiconductors
Product specification
Octal D-type transparent latch; 3-state
FEATURES
•
Inputs and outputs on opposite
sides of package allowing easy
interface with microprocessors
•
Useful as input or output port for
microprocessors/microcomputers
•
3-state non-inverting outputs for
bus oriented applications
•
Common 3-state output enable
input
•
Functionally identical to the “563”
and “373”
•
Output capability: bus driver
•
I
CC
category: MSI
GENERAL DESCRIPTION
The 74HC/HCT573 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/HCT573 are octal D-type
transparent latches featuring
separate D-type inputs for each latch
and 3-state outputs for bus oriented
applications.
A latch enable (LE) input and an
output enable (OE) input are common
to all latches.
The “573” consists of eight D-type
transparent latches with 3-state true
outputs. When LE is HIGH, data at
QUICK REFERENCE DATA
GND = 0 V; T
amb
= 25
°C;
t
r
= t
f
= 6 ns
74HC/HCT573
the D
n
inputs enter the latches. In this
condition the latches are transparent,
i.e. a latch output will change state
each time its corresponding D-input
changes.
When LE is LOW the latches store the
information that was present at the
D-inputs a set-up time preceding the
HIGH-to-LOW transition of LE.
When OE is LOW, the contents of the
8 latches 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 latches.
The “573” is functionally identical to
the “563” and “373”, but the “563” has
inverted outputs and the “373” has a
different pin arrangement.
TYPICAL
SYMBOL
t
PHL/
t
PLH
PARAMETER
propagation delay
D
n
to Q
n
LE to Q
n
C
I
C
PD
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”.
input capacitance
power dissipation capacitance per latch notes 1 and 2
CONDITIONS
HC
C
L
= 15 pF; V
CC
= 5 V
14
15
3.5
26
17
15
3.5
26
ns
ns
pF
pF
HCT
UNIT
December 1990
2
PHILIPS [ NXP SEMICONDUCTORS ]
