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Transient current of logic gate due to change in logic

A logic gate drives a load, which has a resistance of 1 kΩ and a capacitance of 20 pF. The printed circuit track connecting the gate to its load has an 40 pF capacitance to ground. The output changes state from 2.5 V to 0 V in 200 ps.

Determine the maximum output current to find the the initial surge of current for (a) use I=C*dv/dt

Solution Preview

In the steady state when the output is steady at 2.5V no current flows through the load. Effectively we can think of things unchanging in this the DC Domain where capacitances represent DC blocks (ie they have infinite impedances from Zc = 1/(omega*C , where at DC Omega the angular frequency is zero)

In contrast maximum current flows when the capacitance impedance is minimum, again when the output is changing most ...

Solution Summary

This solution involves calculating maximum current draw due to capacitive load of a logic gate when it changes state.