about the power of the mpc8270

[kaizhou]

I am using mpc8270 in my project, but i find a strange question recently. If i leave the vdd voltage floating and supply the vddh 3.3V, the current from the power will increase 0.2A than the situation which supply the vdd voltage 1.5V and supply the vddh voltage 3.3V.

Can you help explain the question?

[alexander_yakov · Accepted solution]

When the core voltage is not applied, but only I/O voltage is applied, this means the device core is not powered, but only I/O buffers are powered. In this case I/O buffers will be in "random" state, driving random output value, either "high" or "low", and extra current may be drawn by the device over this I/O voltage.

Have a great day,
Alexander
TIC

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[kaizhou]

Thank u for your answer, it's so useful。