mheruian
Junior Member level 3
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Hi, I'm new here and maybe this is the best section where I could need help
I've been interested in electronics lately (not schooling anymore, more on self-study, but I'm not that smart, just a dedicated one and i can't understand everything right through). I don't have any equipment yet like osci, etc. Then I thought of doing mathematics on electronic components like integrated circuits (IC) since even though ideal, math in some percentage of little marginal error, result should reflect close to reality (simple math is what I rely on).
Here's where I am at, I'm trying to know the current consumption (minimum and max) of this IC (https://www.ti.com/lit/ds/symlink/sn74hct138.pdf). Upon reading the documentation, I am at first thought it was easy since 80uA was brought up in the description but skimming on the electrical characteristics (image link below) looks like this is the max current consumption when there is no output current (Io = 0) on its decoding output lines.
![current_compute.PNG current_compute.PNG](https://www.edaboard.com/data/attachments/76/76773-6474f7dde7cd5fa48f4ff9affd0d0175.jpg)
That means the IC is in idle state right consuming current just for powering it self up and not for output/decode operation? Then i found the continuous current output and continuous current through VCC or GND? I got confused but still proceeded.
Here's what I computed for getting current consumption for output operation, idle operation, min and max consumption:
Iconsume = Icc + IOL
Iconsume = 80uA + 4mA
Iconsume = 80uA + 4mA
Iconsume = 4.08mA
Imin = 1000nA or 1uA (this is idle state also?)
Imax = 50mA (Maybe an addition how did they get this?)
If I can determine these currents in the 3 states of the IC, I can now know the power consumption of the IC. I hope someone could verify this or correct me and show me how even on a small example.
Here's where I am at, I'm trying to know the current consumption (minimum and max) of this IC (https://www.ti.com/lit/ds/symlink/sn74hct138.pdf). Upon reading the documentation, I am at first thought it was easy since 80uA was brought up in the description but skimming on the electrical characteristics (image link below) looks like this is the max current consumption when there is no output current (Io = 0) on its decoding output lines.
![current_compute.PNG current_compute.PNG](https://www.edaboard.com/data/attachments/76/76773-6474f7dde7cd5fa48f4ff9affd0d0175.jpg)
That means the IC is in idle state right consuming current just for powering it self up and not for output/decode operation? Then i found the continuous current output and continuous current through VCC or GND? I got confused but still proceeded.
Here's what I computed for getting current consumption for output operation, idle operation, min and max consumption:
Iconsume = Icc + IOL
Iconsume = 80uA + 4mA
Iconsume = 80uA + 4mA
Iconsume = 4.08mA
Imin = 1000nA or 1uA (this is idle state also?)
Imax = 50mA (Maybe an addition how did they get this?)
If I can determine these currents in the 3 states of the IC, I can now know the power consumption of the IC. I hope someone could verify this or correct me and show me how even on a small example.