K561TL1
This 4-element 2, NOT with Schmitt triggers on the inputs.
The latter distinguishes the work This mikruhi of all known
logic AND-NOT same K155LA3.
Schmitt trigger changes its state
(And, consequently, the output signal) is sharply - with
gradual change in the input signal within certain limits - to
the border switch. Thus, the switch logic 0 will trigger when
the input signal drops to a level equal to or below Ul0 -
border switching low level, and switch to a logic 1 will, if
the input signal rises to the level of equal to or greater than
Ul1 - border switching high level.
Level Ul1, of course, higher level
Ul0, and if you draw a graph of the
between input and output voltage of Schmitt trigger, it will
loop - the so-called "hysteresis" (as opposed to simply element
with the feature as a line). Loop is sometimes portrayed in the
logic elements with a Schmitt trigger. When the signal level
greater than Ul0, but less Ul1 trigger is not switches, while
maintaining its previous state. Thanks to this single area of
the interference gradual change in the signal are excluded. Ie
on the negligible level of interference that
usually act on any signal (at
the tens of mV), they can not change
trigger status (their amplitude is much
smaller than the width of the blank areas). If only
input signal is not too close
to the boundary shift, and thus the probability of switching
efficiency was high. And in the case of switching under the
influence interference, it would be equally probable (with a
useful point of view) and a single, because for another
switching signal must overcome the entire width of blank areas
- many greater level of interference.
Since the range of food mikruhi of 3
to 15, the boundaries shift also depend on food (almost
linearly), and it is believed that Ul0 approximately equal to
one third of the Ucc (Supply voltage), t.e.nizhe half, and
Ul1 approximately equal to two thirds of the Ucc - ie
more than half the power. Although usually well
denote the permissible limits of CMOS levels
- Technology, not the border Schmitt trigger.
Sources of information are not quite correct ...
Personally, I'm interested in current consumption
(When did amigovskuyu mouse Speccy).
Clearly, it depends on the input voltage, and I spent several
experiments for determine the maximum engorgement
K561TL1. Data kept in mind, and after assembling the mouse just
forgot. When going to write an article - repeated the
experiment, but with the foreign analogs MC14093BCP, and
suspected the difference (although the schema mouse
irrelevant). When there was K561TL1, decided to completely
razobratsya with this issue. As a result, screen appeared and
the text.
At the same time decided to write on the screen of the
schedule Log RADIO 6 / 90, although suspected
it is wrong (in low power boundary Ul1
dropped below half power). Still there
unsavory information about inverting Schmitt trigger. It
appeared that a 4 Schmitt trigger with the logic-2, NO, and
would be expected to single
switching, if applied to one input 0 (and
the second did not react - according to the logic element).
Although in itself trigger Schmitt is not associated with any
logic - This simple device, with input and output.
As a result, found out the following.
Like all mikruhi 561 series, this does not consume the input
current (of course, not counting leakage currents) and consumes
negligible Supply Current (I did not to measure this shameful
value) if the input signals are close to 0
or supply voltage. Of course, the outputs
I does not load, and connect to them
Digital multimeter M832 (input impedance 1 Mohm - close to the
load currents leakage can be ignored).
The same device I sometimes controlled
food mikruhi (putting him on a laboratory unit equal to 3.5 V),
but mostly I they took it for the input voltage, namely voltage
supplied from the divider - the multi-resistor 10 k ohms,
shunted capacitor from interference. This allowed us to get
closer to the borders of trigger close enough to assert their
value.
If there was a divider, as I took it for electricity? A
very simple: just 7 feet
sockets through another device on the negative supply. This
device has been TS20-05. When disadvantage of using (a set of
jacks), he has a high sensitivity (collected
on an operational amplifier) and almost no effect on the
measured circuit. Where would all testers believe? I can only
say that the maximum error was less stress 5%, and the currents
are less than 8%. Nutrition mikruhi was 5 V + - 0.02 V. The
temperature in komnote 22 degrees (possible slight drift
parameters mikruhi temperature).
At first, I decided to check one input. Gave him the voltage
from the divider and the other, to eliminate the influence by
connecting plus food. When approaching the limits
switch (k Ul0, if the trigger was switched to 1, and Ul1, if 0)
the current consumption increased (t.k.rosli switching
currents), reaching a maximum on the boundary shift, and
immediately after the switch drops sharply to a small value -
t.k.vhodnoe stress significantly different from 0 and supply
voltage.
I spun the divider in the opposite direction,
closer to the opposite boundary, the
which the process was repeated: first, the current increased,
then the trigger was switched, and the current drops sharply.
Several times carefully selecting the borders, I wrote them
down voltage and associated power consumption. Then put the
import mikruhu and repeated the experiment. The result was very
different to current (Had to change the range of the tester).
Then I switched to the unused inputs
plus to minus, the outputs of the permanently switched to the
unit, and repeated the experiment with the same input and both
mikruhami. According to the magazine, radio, the input should
not was switched trigger (once the item is already
switched the output to 1).
Yes, of course, the output was always 1. But!
All my measurements were repeated without change. Toggle
flip-flop has been seen by a sharp decline in the current
conventional boundaries.
Maximum current consumption by a trigger
Schmitt input element (one trigger /
input, respectively), with appropriate switching threshold,
measured at nutrition Ucc = 5V, outputs unloaded and
other inputs are connected to plus or minus supply:
Domestic chip K561TL1
Ul0 = 2.14V Icc = 0.3mA, Ul1 = 3.17V Icc = 0.41mA
Import (MOTOROLA) analog MC14093BCP
Ul0 = 1.98V Icc = 0.11mA, Ul1 = 3.21V Icc = 0.11mA
I am sure that this is the current trigger
Schmitt, instead of an AND gate, NOT, etc.
since an element of the trigger ready to come
logic levels are equal to 0 or voltage
nutrition, and, as always in such cases, through current is
absent. Of course, when switching element uses a certain
current, but only a very short time - a time switching, it does
not even measure a simple way. In the rest of the time (and the
majority) can be assumed that the element does not take energy
(in the absence of stress, of course).
I measured the current consumption of a trigger (and them as
inputs, 8), and one can simply multiplying by 8 to calculate
the maximum current consumed by a chip with no load,
at 5V. But the possible spread of parameters of different
inputs, and I decided it vyyasnit.Dlya by connecting all the
inputs together, to the divisor, and repeated the experiment
for both chips.
By switching threshold approached very carefully, t.k.u some
inputs are could be known to me earlier values.
I watched as the value of current increases and
near the boundary drops sharply back. I write this voltage
switching and carefully turn the border - another sharp
decline, off the record. Further movement abroad leads to a
gradual decrease current consumption.
Consequently, all the triggers already switched. Move back
to the other border. All repeats, triggers switch 2 - 3 sharp
current fall in a narrow range of input voltage. Theory
multiplication by 8 is essentially confirmed. And imported
chips was so large (about our) scatter Ul0 inputs, I (arrow
tester - ammeter) watched all 8 downturns - Switching triggers
on the inputs. Repeated the experiment several times and
adjusted the measured values.
Maximum current consumption without the chip load for Ucc =
5V and the voltage on all inputs is equal to:
Domestic chip K561TL1
Ul0 = 2.16V Icc = 2.5mA, Ul1 = 3.17V Icc = 3.4mA
Specified limits at which triggers another
pereklyuchilis.A not completely switched
(All) at: Ul0 = 2.13V, Ul1 = 3.19V.
Import (MOTOROLA) analog MC14093BCP
Ul0 = 2.04V Icc = 0.83mA, Ul1 = 3.21V Icc = 0.88mA
Specified limits at which triggers another
pereklyuchilis.A not completely switched
(All) at: Ul0 = 1.91V, Ul1 = 3.25V.
According to the results of experiments we can say that
Each input circuit is provided with an independent
Schmitt trigger, the most consuming
energy on the boundary shift (in our
mikruh border Ul1, in this foreign analogues in any border),
and not counting load on the output circuit, this current
consumption is fundamental. It's a little
denied information from the magazine radio,
incorrectly describes the elements mikruhi.
Analyzing the switching boundaries can be
say that they (at Ucc = 5V) lie on both
side of half the supply voltage,
and Ul0 little more than a third supply, and Ul1
slightly less than two-thirds power. This indicates an
inaccuracy in the schedule of the journal (Low value Ul1).
Likely edited by simply copied the information sent to them
from one of the readers are not checked. The man could not take
into account the error measurement introduced by the device
into a voltage divider (if devices were more simple and less
sensitive). However, it is likely that produced when
mikruhi differ from the present, which I
doubt.
However, the difference between reduced chips - is obvious.
Despite the similar values Ul1, they have markedly different
Ul0, and the asymmetry of power on the borders of our
mikruhi to the symmetry of the current import
indicates a different scheme Schmitt trigger.
The large difference in current may indicate
the difference in chip manufacturing technology (as well as
letters of BCP in the name of analogue). But perhaps the reason
the block, the standard the structure of our mikruhi. Her
flip-flops (they output stage) are calculated on a standard
CMOS load, rather than one entry inside the chip. Therefore,
these voracious and import trigger recalculated taking into
account the follow-unit load.
Despite the relative engorgement, it is impossible to say
that our chip huzhe.Ona even more sensitive to the signal
(voltage Ul0 Ul1 and closer to each other than imports), and a
small plus to use a mouse. Incidentally, the maximum current
consumption chipset slightly more than that (since the border
operation consistent with the very sensitive input, the rest
were not at the limit, and their power values were below the
limit), but indeed the maximum currents, probably not
max: 2.6mA (at Ul0), 3.5mA (at Ul1) -
K561TL1; 0.9mA (Ul0 or Ul1) - MC14093BCP.
And with the spread of performance, no more
3 - 4 mA at 1 mA, and our imports have mikruhi. In the
calculation of universal schemes, without reliable information
(not a specific, proven mikruhu) I usually double the known
(measured) value of consumption current.
I believe that the current import mikruhi on
boundaries are almost equal (this follows from the measured
values). Despite the difference in 0.05 mA, the threshold for
triggers Ul0 was with a spread of nearly 0.13 V, which explains
the difference between the current at Ul0 and Ul1. Disorder,
clearly permissible, t.k.nebolshoy about 5V, but it's a little
minus.A here more symmetry currents and voltage limits - A
small plus. Mikruhu characterizes our little spread on the
borders - a sign of high-precision performance (but maybe
technology is not so tiny and so easy to repeat).
It remains to mention the multiplicity of current. She
almost equal to 8 - proving the number and independence of the
triggers. But the import of chips really Ul1 8: 0.11mA * 8 = =
0.88mA. And Ul0, taking into account the scatter, it so, too.
Our mikruhi currents slightly higher than calculated ,8-fold,
znacheniya.Vozmozhno, it is only because of the spread of
triggers for the current and, possibly, on the border switching
output voltage triggers significantly different from 0 and
supply voltage, provoking a low current leakage through the
gate. The latter circumstance is a small drawback (maybe a
little reduces the load current gate on the verge of
switching), and on every case should take this into account.
The result of the comparison.
Both mikruhi worthy of his appointment
and can be successfully used in the mouse.
Our chip is slightly more sensitive to input levels and more
accurate on the Limits response, but voracious current. Import
chip economical and more symmetrical the levels and current
consumption, but with a noticeable spread in the level of
switching logic 0.
By KSA-7G 11.2003
