Initial Designs of an on-Chip EMI Sensor Array

Abstract

The purpose of the on-chip EMI sensor array (OCEMISA) is to measure the 2-dimension profile of the EMI voltage in the on-chip power distribution network in real time. The feedback signal from a senser cell should reflect only its local EMI. Signals have to be grouped carefully. This paper presents two different designs of the OCEMISA. In the first design, sensor cell generates regular pulses as feedback. The time domain waveform is monitored. In the second design, the supply noise generated by the sensor cell is utilized as feedback. The spectrum is monitored. Designs are implemented with FPGA for validation check. Measurement results show that feedback signals faces synchronization and instability problems. Those problems come from the IC process variation and are influenced by the feedback scheme. With the presentation and analysis of those problems, the paper is intent to provide optimization directions to make OCEMISA practical.