A voltage sensor for a voltage controlled interface of a plasma processing system. The voltage sensor receives a RF signal generated by a pickup device. The RF signal is indicative of a RF voltage provided at a substrate in a plasma chamber. The voltage sensor includes first and second dividers corresponding to first and second channels and having first and second capacitance ratios. The dividers receive the RF signal and respectively generate first and second reduced voltage signals. A first output of the first channel outputs a first output signal based on the first reduced voltage signal and while the RF signal is in a first voltage range. A second output of the second channel outputs a second output signal based on the second reduced voltage signal and while the RF signal is in a second voltage range.