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/spl times/10/sup 7/ 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.

Introduction

As the process technology advances, the transistor count in a LSI chip has been increasing, the operating frequency has been getting higher, and the supply voltage has been getting lower. Thus, the power supply noise is getting a critical issue from the signal integrity point of view.