Saelig Company, Inc offers the Micsig SigoFIT Series Opto-isolated Probes, which have excellent amplitude/frequency characteristics and provide an excellent common mode rejection ratio (CMRR up to 112dB at 100MHz, over 100dB at 500MHz.) The full-range noise floor is 1.1mVrms max, and the 24-hour zero drift is less than 50uV. These probes feature Micsig's exclusive SigOFIT optical isolation technology, remotely powered by laser light or battery, offering extremely high isolation voltage to help engineers to see true, uncorrupted signals within their specified bandwidths.
Five bandwidth models are provided for signals from 100Hz to 1GHz, with the measurement heads either battery-powered or opto-isolated LED laser-powered. The input test leads of the SigOFIT probes are short and have coaxial cables for transmission from the measurement heads. They present less than 3pF input capacitance load, which makes these probes excellent for testing SiC and GaN devices that can switch high voltages in a few nanoseconds and produce very high-energy high-frequency harmonics. Unlike traditional differential probes, which can only test high-voltage signals, the series probes can be utilised with different attenuator tips to test differential mode signals from ±1V to ±2500V, achieving full-range output and a very high signal-to-noise ratio. Smaller than traditional differential probes and with more precise probe tips, SigOFIT isolated probes are easier and more versatile than conventional differential probes. With a very fast response, signals can be tested immediately after power-on without waiting for a warm-up period. Autozeroing in less than one second ensures accurate signal measurements in real-time. Even at the highest bandwidth, the SigOFIT probes still have approximately 100dB CMRR to suppress oscillations caused by high-frequency common-mode noise perfectly.
Applications include the design of motor drive, power converter, and electronic ballast; design and analysis of GaN, SiC, and IGBT Half/Full bridge devices; design of inverter, UPS and switching power supply; safety test for high voltage, high bandwidth applications; power device evaluation; current shunt measurements; EMI and ESD troubleshooting; and floating measurements.