Study on LDO Susceptibility Measurements Based on Direct Power Injection Method

Abstract

Susceptibility level of low-dropout regulator (LDO) is measured based on direct power injection (DPI) method in this paper. Hardware and software of standard DPI test bench is set up with test flow and algorithm being optimized. Extraction of injection power is analyzed, and impedance simulation validates the test which is carried by vector network analyzer (VNA). A test chip of Elmer2 which is dedicated to EMC study is used for DPI measurements. The failure mechanism of LDO module in Elmer2 is studied under EMI. On-chip sensor is also used for interested nodes voltage extraction with probability and statistical methods, susceptibility level is further found out with on-chip measurements. After comparison with traditional test method, this technique has optimized DPI method which can develop the applications of susceptibility measurements for complex devices.