On-chip di/dt detector circuit for power supply line

This paper describes an on-chip di/dt detector circuit for power supply lines. The di/dt detector consists of a spiral inductor under the power supply line and a noise-tolerant amplifier. The former induces a di/dt proportional voltage by means of mutual inductive coupling, and the latter amplifies the induced voltage linearly. Simulation results show that the detector can measure the di/dt with an accuracy of 1.52×10⁷ A/s. The current waveform can be obtained by integrating the di/dt, and the result shows 0.72 mA accuracy at an average current of 50 mA.