I have a question regarding calculation power consumption of a circuit. I have a rather large circuit that I am trying to figure out the total power consumption for. My question is how do you calculate the consumption of each device, realizing that P=VI? For example, take a schmitt trigger that is being supplied with 3.3 V. Would I calculate the estimated power consumption by taking the Icc supply current and multiplying it by Vcc? Alternatively, do I take the output current and multiply it by the output voltage? My reason for doing this type of analysis is to decide if the power supply that I am using for all of my circuits is sufficient. Thank you in advance for any help.