Contactless scribe-test monitor with photovoltaic power, VLC downlink and IR-UWB uplink

A contactless scribe-line channel-leakage monitor with relaxed alignment requirement is described. It comprises photovoltaic converters for powering from indoor illumination, a visible light communication downlink for selecting one among multiple monitors, and an ultra-wideband impulse-radio uplink for transmitting the measured leakage data in the form of impulse repetition frequency. Readout is accomplished with an external loop antenna loosely aligned to the scribe-line transmitter antenna. The proposed monitor was implemented in 0.18-μm CMOS with a footprint 4960 μm × 160 μm including the transmitter antenna. It deploys a novel leakage sensor of ring-oscillator topology. All circuit blocks, except for the transmitter, are power-supplied directly by photovoltaic converters without regulation, and consume 64 nW. Transmitter is powered by an integrated storage capacitor charged to 1.8 V by a photovoltaic-powered voltage booster.