Inferno #08 30 ноября 2005

Железо

Iron - Description of Products K555TL2.

          K555TL2

   IC K555TL2 contains six investment
pTop NOT, each with a Schmitt trigger for
input. For this reason, switching output
a logic 0 or 1 is determined by
voltage divider - threshold
on vhode.Vnutrennyaya positive feedback
Contact covers the input stage, changing its
sensitivity to input voltage. A
because internal communication is very high,
then input voltage can be tough
tied to any signal or Shun
capacitor are oriented in any capacity, and this
not affect the switching speed of the elements
ment. The only thing that should be considered
(Apart from the impact of interference and dependence
thresholds of nutrient stress
line) - so it's parasitic dependence WMOs
dnogo current member of its logic from
standing, not only on the input voltage
of, and actually throw the input current -
his abrupt change when switching locally
topological element. This explains the internal
an interior coupling. This effect can even be used
use to control current rather than
voltage, but the boundaries of change in the current difficult
control. To reduce the parasitic
impact on entry and stabilization of thresholds
response (increase the accuracy of tripping
tion) should reduce the input resistance
Equation (operating current - mA), then
input currents will be immeasurably less then
Cove control, set the input voltage
(For example, the resistor connected to
entrance to the minus sign).

   As always in such cases, I use
shaft sockets and multi-turn resistor, but
because it is not CMOS chip, and the WMO
holes consume significant current, I connected
to the inputs through the emitter follower.
Old tester TS20-05 used for measuring
measurements of current consumption of the chip itself, the
minus food at the limit of 30mA (this closely
ter avoids some of the modern digital
devices in sensitivity, due to the scheme
metal, built on the operating amplifier, and
has a very low voltage drop
when measuring the current that is necessary to point
Nogo experiment). Tester M832 using
valsya for voltage control and input
currents, but the greater accuracy of measurement
input currents, I did not expect. In summary:
current consumed by a chip on the positive,
is the sum of current consumption of the elements themselves
Comrade (Ip - indicated here and in the scheme) and their
Input Current - depending on ex
ments and operations. But the total current
lies in the range 9 .. 13 mA and noticeably excited
increases at frequencies above 1 MHz (assumed
lag, did not check!).

   Inputs TTL chips are made by those
technology and work "to 0", ie from unity
(+ Food), they may drain is difficult to
measurable leakage current, and we can assume that
Current non-existent, and when connected to "-" -
logic "0" with input implies a noticeable
control current. This current depends on input
Nogo voltage logic state to
output of the element, because this condition
determined by a Schmitt trigger that effect
yaet through internal feedback to
entrance. All this explains the interesting
dependence on the input current changes
voltage at the input, measured at the same time
for all inputs - joined together. When
reducing the input voltage (until you
During the "0") to 0.79 V, the current inputs rises
to 1.18 mA, and this is sufficient
to change any element. By
following which it affects Schmitt trigger
the input by shifting its threshold, that is to
creased input current (but only this - already
switched to "1" element). In fact,
it should mean a drawdown of input
voltage (in the direction of its increase) - once
current on one input increased, and thus Snee
the probability of switching to reap other trigger
Gere, as they need a few more current
for this (and we stress subsided, and
Accordingly, the current in the remaining
inputs), but dynamically it is possible - I
hung on the input capacitors, which are not
will instantly change the input on
voltage and current. A resistance tester
M832, when I took it for the input current, we can not
considered significant, because they do I measure and
Input Voltage - and then he did not
could shift the dynamic potential, and as a result
result - grupovoe switching triggers
was in both cases. But, apparently, due to the PA
razitnoy intercom Nutrition sum
Marne inrush current input was Perek
Luciano and all the triggers at once will switch
were in the "1". In this case, the total input current
rose to 1.23 mA.Tut I started to raise UNE
mummers at the input current is, of course, was to reduce
camping, and when it reached 0.95 mA (at voltage
1.64V), all triggers are switched to "0" and
input current has disappeared. Again, imagine that
first switched to a single trigger, and the mixture
Teal switching threshold, and the input variables pn
the course was closed, and the current of this entry 
ischez.Togda total input current is decreased, and the input

voltage was slightly lower, and the currents remaining
GOVERNMENTAL trigger input - a little more, then
we can assume that the input signal with variable
exception of one flip-flop just moved
Switching from the border of others, and requires
it further shifted to
worked the other triggers. But the dynamic
ski (see the above), the displacement input
voltage is possible, or no effect on that
fact that all triggers are switched one
temporarily. After switching the input current
disappears as the internal communication of
triggers shifts the threshold voltage, and
input pn junctions are closed
(The difference between internal stress and
External insufficient for their opening).

   Despite the fact that controls switching
Niemi input voltage is not as current (as
throughout the TTL-based input), I was not his
measure for an individual item. Driving
shock, do not rely on the correct
work, in some cases it is appropriate -
for "frivolous" devices, which allowed
errors in their work. Approximate threshold of a CPA
batyvaniya current administration, respectively
but 6 times smaller than the above for me
All 6 elements, and about the estimated
the result is enough to construct
of schemes managed by the current. The threshold of transition
switchover of one item from "0" to "1" -
approximately 0.2 mA, and from "1" to "0" - approximately
0.16 mA (do not forget that I am describing OTE
tively chip K555TL2! For other
series and similar imported currents can si
flax differ, but the voltage will be almost
are the same (naverno. ..)).

   When a voltage 4.95 V and free WMOs
dah chip consume 12.7 mA, while you
speeds (I've never loaded the experiment at their
experiment), of course, were "0" = 0.07 V. At
inputs nameryalos 1.24 In Idling voltage
tion, but all together Inlet
it was already 1.33 - affects the sensitivity
sequence of input and undervoltage Th
Res tester. Total current closed on the target
nous input is 1457 mA, Ip at the same time
decreased to 7.8 mA and the output was "1"
= 4.31 V. If only one entry (the rest
hang loosely) connected via a 1 kOhm to
negative - on it in 0.24, the output of this element
ment 4.31 V, and Ip = 12 mA, thus
each switch in the "1" is the trigger lowers
tokopotreblenie chips by about 0.7
mA, but the input current in this case may provide
exceeds 0.25 mA.Razbros Input Current (uA)
and stress (B) thresholds for
All 6 elements:

from "0" to "1" 0.78 0.77 0.79 0.80 0.77 0.79
from "1" to "0" 1.67 1.66 1.68 1.67 1.65 1.66
talk to "-" 245 250 246 252 243 240


   Based on these data, the spread of the highly
Metheny, and triggers would not switch
simultaneously, even connecting to the same
signal, but once it did, there is
individual causes - parasitic dependence
of power, which manifests itself in
stages of the chip. This follows from the appreciable
Nogo difference between current consumption in different
logical state of flip-flops. Recall
Schmitt trigger CMOS chips - there I Th
TKO fixed the trigger firing in
different times, including on
consumed mikruhoy current at that
spread triggers have been imported mikruhi
very small, and sometimes work directly carried
How many flip-flops - some but not all
at once! It turns out that CMOS technology is here
bypassed TTL (TTLSH - K555 series), despite
high error-sensitivity (as usual
think of the enormous resistance to
entrance). Of course, unlike CMOS, our TTLSH
mikruha can work on dozens of MHz,
allowing you to generate, hold and formation
rovat very short pulses, but we need
be able to handle it, given the probability
sequence triggers activation of neighboring syn
chrono each drugom.Eto can even when r
ditsya in the schemes of synchronization signals.
But in other cases, use
triggers a sequence for mikruhi
Noah delay - the spread of a single cross
theory of pulses, or different, but synchronous (from
one quartz) pulses with a noticeable separation
leniem formed during the time of fronts.

   If you need just to delay any
digital signal for computer use
emitter follower and diodes to decrease
level of logic 1. For example, file
signal at the base of the transistor KT315 (B, D)
collector to +5 V, with the emitter in a couple of
silicon RF diodes on the two resistors 330
Om.Odin of resistors on the negative and the second on
entrance to our mikruhi, but shunted with
corresponding capacity. Picking capacity
(Coarse) and the input rezyuk (exactly), it is possible to
beat a very stable delay at the output
de elementa.Dlya even better results can
zhno "negative" resistor to replace generators
torus toka.Kondensator should have
as close to the entrance, and the transistor -
to the exit (the detainee signal).



   This information is lain on the shelf
- On paper - perhaps more than a year
and I can not rule out any mistake in
Data Recovery, even though everything seems
logical.

11.11.2005
KSA-7G