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I am reading and trying to understand datasheet of ICs.
I am reading this datasheet now : http://www.ti.com/lit/ds/symlink/sn74hc00.pdf
In the table 6.5, there are two parameters namely Ii and Icc. Input current and supply current.
I would like to understand the difference between the two terms?
Can someone please explain with some example for understanding.
Thanks.
\$I_I\$ is the input current into an input.
Even though it isn't mentioned in the datasheet, I derive this from the fact that \$V_I\$ in table 6.3 is the input voltage, then it is "logical" that \$I_I\$ is the input current. This current is supposed to have a very small value which makes sense as this is a CMOS inverter and CMOS logic is supposed to have extremely small input currents.
\$I_{cc}\$ is the current flowing into the supply pin \$V_{cc}\$
Note that any current that is delivered (to a load) by the inverters also flows into the IC via the \$V_{cc}\$ pin. We want to exclude these currents so that's why it says: \$I_o = 0\$
The only current that flows in this test are leakage currents which are supposed to be small that's why there is only a maximum value listed.
Ii is the input current into a gate. Up to 1uA (1000nA) max.
Icc is the chip supply current. It is listed as very little with no loads attached.
The glossary in 12.7 does not seem to address either one. Perhaps the terms are listed in some of the other reference documents.
