Can current flow one way or both through a 7400 series inverter gate?

Question

In other words is it
A) current can flow through an inverter in either direction (inverter doesnt care)
Or
B) current will only invert correctly when going through one side of the inverter.

Answer 1

B

Current will not flow at all in reverse direction - actually voltage level does not transmit back

With certain exceptions, all 7400 devices are voltage operations - while an output will source one current amount and sink another in the ratings the source is the power supply and the sink the ground not the upstream circuitry.

Answer 2

7400 is not a resistance for current to flow in or out. It is an inverter where "input" has some specifications and so does "output". The input has a voltage specifications generally understood and also has some current specifications often not understood!. The input should be less than 0.4V for a 'zero" level input. In such a case, a current flows output of 7400 into the source, of the order of 1.6mA. Thus the source providing a zero has to also eat this current, and pretend that nothing has happened, meaning the voltage remains same. A resistor R in series with the such a source will mean that apart from the source voltage, a voltage of 1.6mA * R is the actual voltage presented to 7400. Thus placing a resistor of just 250 ohms from gnd to input will mean that voltage fed to 7400 is not zero, but about 400mV.

Though 800mV is acceptable as max "zero" level voltage, 400mV of this is kept as reserve for combating noise.

Similarly an input of 2.4V will ensure that a High level is fed as input. the current in this case of 40uA flows from source into the device, 7400. That much about input.

About output: The 7400 has ability to sink 16mA and still ensure that output is less than 0.4V, when outputting a LOW. When outputting a High which is guaranteed to be less than 2.4V, the device can at best be expected to source a current of 400uA. thus one can only connect to gnd a load of 2.4V/400uA or 6k as load. This is TTL loading rules.

AND THE FUNCTION OF 7400 IS INVERSION. If input is a LOW, output is a high, provided of course that you provide a supply voltage of about 5V.

To understand more, download lessons in electric circuits by Kuphaldt from DISCOVER CIRCUITS and see digital chapter.

Answer 3

while you're in 5th grade, then according to threat the respond may be "No modern-day flows by using insulators via definition of an insulator" yet once you're interior the actual international, lots of the different solutions are the appropriate option, the present is so minimum. in spite of if, some insulators do have countless resistance yet in basic terms at low voltages. you elect loose electrons to bypass electron modern-day. yet as you improve the voltage around the insulator in some unspecified time interior the destiny, the urge for the electrons to bypass will rigidity any fabric to resign that is electrons and bypass them down. So, no count how sturdy the insulator, in case you have sufficient voltage, it is going to start to habit. that is like funds... in case you have sufficient, you may purchase something!! (even youthful human beings).

Answer 4

if you need a switch that transfer from either side to the other side, look at transmission gates in cmos logic.



or else use a 7400 series device to turn on a fet transistor that acts as your transmission gate.

Answer 5

B.