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Anil Kumar Bajiya posted an Question

August 24, 2020 • 02:59 am

30 points

IIT JAM
Physics (PH)

What is meant by active low output and active high input?

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Dhairya sharma

It is not the transition, 0-to-1 or 1-to-0, which defines active low or active high, but instead it isthe "absolute" voltage of the signal, Vdd or ground in most circuits (Vdd is usually 2.2 V or 3.3 V in current digital devices nowadays). When the devices (or, more precisely, device inputs) are sensitive to transitions they are called edge-triggered (positive edge triggered if sensitive to 0-to-1 transition, negative edge triggered in the opposite case). For a given input, being edge triggered is not the same as being "active high or low". Finally there is another related concept in digital circuits which is "positive logic" or "negative logic"; in positive logic, the logic (or Boolean) '1' or 'High' corresponds to the higher voltage in the device, which in general is Vdd; in negative logic, the '1' or 'High' corresponds to ground (0 Volt). In many practical circuits you can find a mixture of all the above concepts ;-)
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Dhairya sharma

It is not the transition, 0-to-1 or 1-to-0, which defines active low or active high, but instead it isthe "absolute" voltage of the signal, Vdd or ground in most circuits (Vdd is usually 2.2 V or 3.3 V in current digital devices nowadays). When the devices (or, more precisely, device inputs) are sensitive to transitions they are called edge-triggered (positive edge triggered if sensitive to 0-to-1 transition, negative edge triggered in the opposite case). For a given input, being edge triggered is not the same as being "active high or low". Finally there is another related concept in digital circuits which is "positive logic" or "negative logic"; in positive logic, the logic (or Boolean) '1' or 'High' corresponds to the higher voltage in the device, which in general is Vdd; in negative logic, the '1' or 'High' corresponds to ground (0 Volt). In many practical circuits you can find a mixture of all the above concepts ;-)
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go through the article as well
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Dhairya sharma

for any query drop a comment
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Dhairya sharma

hope u got it dear
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ys,, thank you mam
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Dhairya sharma

A signal is 'active low' means that signal will be performing its function when its logic level is 0. A signal is 'active high' means that signal will be performing its function when its logiclevel is 1.
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but esme output or input nhi btaya..
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