Monitoring effective supply voltage within power rails of integrated circuits

An effective supply voltage monitor evaluates dynamic variation of (V_dd-V_ss) within power rails of integrated circuits on a die. The monitor occupies an area of as small as 10.8 × 14.5 μm² and is followed by backend digitizing circuits, both using 3.3 V thick oxide transistors in a 65 nm CMOS technology for covering all power domains from core circuits to peripheral I/O rings. A prototype demonstrates capturing of effective supply voltage waveforms in digital shift registers as well as in an array of analog comparators.