N74F5074D,602 NXP Semiconductors, N74F5074D,602 Datasheet - Page 3

IC FLIP FLOP/CLOCK DRIVER 14SOIC

N74F5074D,602

Manufacturer Part Number
N74F5074D,602
Description
IC FLIP FLOP/CLOCK DRIVER 14SOIC
Manufacturer
NXP Semiconductors
Series
74Fr
Type
D-Typer
Datasheet

Specifications of N74F5074D,602

Function
Set(Preset) and Reset
Output Type
Differential
Number Of Elements
2
Number Of Bits Per Element
1
Frequency - Clock
120MHz
Trigger Type
Positive Edge
Current - Output High, Low
15mA, 20mA
Voltage - Supply
4.5 V ~ 5.5 V
Operating Temperature
0°C ~ 70°C
Mounting Type
Surface Mount
Package / Case
14-SOIC (3.9mm Width), 14-SOL
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Delay Time - Propagation
-
Other names
568-1732-5
935007610602
N74F5074D
Philips Semiconductors
LOGIC DIAGRAM
DESCRIPTION
The 74F5074 is a dual positive edge–triggered D–type featuring
individual data, clock, set and reset inputs; also true and
complementary outputs.
Set (SDn) and reset (RDn) are asynchronous active low inputs and
operate independently of the clock (CPn) input. Data must be stable
just one setup time prior to the low–to–high transition of the clock for
guaranteed propagation delays.
Clock triggering occurs at a voltage level and is not directly related
to the transition time of the positive–going pulse. Following the hold
time interval, data at the Dn input may be changed without affecting
the levels of the output.
The 74F5074 is designed so that the outputs can never display a
metastable state due to setup and hold time violations. If setup time
and hold time are violated the propagation delays may be extended
beyond the specifications but the outputs will not glitch or display a
metastable state. Typical metastability parameters for the 74F5074
are:
function of the rate at which a latch in a metastable state resolves
that condition and T
the propensity of a latch to enter a metastable state.
Metastable Immune Characteristics
Philips Semiconductor uses the term ’metastable immune’ to
describe characteristics of some of the products in its family.
Specifically the 74F50XXX family presently consist of 4 products
which will not glitch or display an output anomaly under any
circumstances including setup and hold time violations. This claim is
easily verified on the 74F5074. By running two independent signal
generators (see Fig. 1) at nearly the same frequency (in this case
10MHz clock and 10.02 MHz data) the device–under–test can be
often be driven into a metastable state. If the Q output is then used
to trigger a digital scope set to infinite persistence the Q output will
build a waveform. An experiment was run by continuously operating
the devices in the region where metastability will occur.
September 14, 1990
V
GND = Pin 7
CC
Synchronizing dual D-type flip-flop/clock driver
RD
SD
CP
= Pin 14
D
3, 11
1, 13
2, 12
4, 10
ps and T
0
o
represents a function of the measurement of
9.8 X 10
6
sec where
represents a
SF00585
5, 9
6, 8
Q
Q
3
When the device–under–test is a 74F74 (which was not designed
with metastable immune characteristics) the waveform will appear
as in Fig. 2.
Figure 2 shows clearly that the Q output can vary in time with
respect to the Q trigger point. This also implies that the Q or Q
output waveshapes may be distorted. This can be verified on an
analog scope with a charge plate CRT. Perhaps of even greater
interest are the dots running along the 3.5V volt line in the upper
right hand quadrant. These show that the Q output did not change
state even though the Q output glitched to at least 1.5 volts, the
trigger point of the scope.
When the device–under–test is a metastable immune part, such as
the 74F5074, the waveform will appear as in Fig. 3. The 74F5074 Q
output will appear as in Fig. 3. The 74F5074 Q output will not vary
with respect to the Q trigger point even when the a part is driven into
a metastable state. Any tendency towards internal metastability is
resolved by Philips Semiconductor patented circuitry. If a metastable
event occurs within the flop the only outward manifestation of the
event will be an increased clock–to–Q/Q propagation delay. This
propagation delay is, of course, a function of the metastability
characteristics of the part defined by
The metastability characteristics of the 74F5074 and related part
types represent state–of–the–art TTL technology.
After determining the T
between failures (MTBF) is simple. Suppose a designer wants to
use the 74F5074 for synchronizing asynchronous data that is
arriving at 10MHz (as measured by a frequency counter), has a
clock frequency of 50MHz, and has decided that he would like to
sample the output of the 74F5074 10 nanoseconds after the clock
edge. He simply plugs his number into the equation below:
MTBF = e
In this formula, f
input event frequency, and t’ is the time after the clock pulse that the
output is sampled (t’ < h, h being the normal propagation delay). In
this situation the f
because input events consist of both of low and high transitions.
Multiplying f
clear that the MTBF is greater than 10
formula the actual MTBF is 1.51 X 10
SIGNAL GENERATOR
SIGNAL GENERATOR
(t’/t)
I
by f
/ T
C
o
C
f
I
C
is the frequency of the clock, f
will be twice the data frequency of 20 MHz
gives an answer of 10
f
I
Figure 1. Test Set-up
0
and t of the flop, calculating the mean time
D
CP
10
10
and T
seconds or about 480 years.
Q
15
seconds. Using the above
Q
Hz
0.
2
. From Fig. 4 it is
TRIGGER
INPUT
Product specification
I
is the average
74F5074
DIGITAL
SCOPE
SF00586

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