Patent ID: 6879178

Claim:
A method for measuring current, comprising: determining a voltage V(t) in situ at a power input of a die while running a computer process on the die; calculating a Fourier transform of the voltage F f (V(t)) from the voltage calculating a current at the power input of the die in the frequency domain (F f (I dd (t))) using the equation F f ⁡ ( I dd ⁡ ( t ) ) = F f ⁡ ( V ⁡ ( t ) ) Z f , where the impedance Z f comprises an impedance of a power supply loop coupled to the power input as a function of frequency; and determining the current I dd (t) at the power input of the die in the time domain by calculating the inverse Fourier transform of the current in the frequency domain F f (I dd (t)).