Analysis of Output DC Level Shift of On-Chip Voltage Regulator Module using DPI Method

The latest process technology requires wide bandwidth voltage regulator modules. However, wide bandwidth induces low electromagnetic interference immunity problem. Though the susceptibility of voltage regulator modules has not been deeply investigated in the view of output DC level shift. In this paper, the effects of interference in wide bandwidth voltage regulator module are simulated and discussed. The voltage regulator module (VRM) used in this work consists of two stage CMOS operational amplifier and feedback loop with 1.2 V supply voltage. We find out that output DC level shift occurs and the amount differs as higher frequency noise is injected. Also we figure out the noise tolerance with respect to input forward power for different VRM bandwidth conditions.