Optical-fiber Isolated Probe

With Micsig’s exclusive SigOFIT™ optical isolation technology, the SigOFIT probe delivers 160dB CMRR at DC, over 100dB at 500MHz, and able to test differential mode signals from ±1.25V to ±2500V when using with attenuators, present true signal you’ve never seen. It’s the most ideal method for isolated probe technology.

Key Features

Up to 1 GHz bandwidth

160 dB CMRR at DC

Over 100 dB CMRR at 500 MHz

60 kVpk Common mode voltage range

Up to ±2500V differential input voltage range

1% DC gain accuracy

Autozero in less than 1 second

Support all BNC-type oscilloscopes

  • Present True Signal

    SigOFIT probe has highest common mode rejection ratio, or CMRR, up to 112dB at 100MHz, over 100dB at 500MHz. It’s the ultimate referee of signal fidelity measured by other voltage probes.

  • Highest Accuracy

    SigOFIT probe has excellent amplitude-frequency characteristics,  and the DC gain accuracy is better than 1%. The maximum noise floor within the range is 1.41mVrms, and zero drift is less than 500μV after warm-up.

  • Best Probe for Third-Gen Semiconductor

    SiC & GaN device can switch high voltages in a few nanoseconds, the signal may have high-energy high-frequency harmonics.

    Even at the highest bandwidth, the SigOFIT probe still have nearly 100dB CMRR, perfectly suppressed the oscillation caused by high-frequency common-mode noise, no redundant components. It’s the best choice for 3rd-gen semiconductor test & measurement.

  • Safe to Test GaN

    The test leads of SigOFIT probe are short and with coaxial cable transmission, has less than 3pF input capacitance, very safe to test GaN.

    * When the working parameters of the device are already in the critical state of explosive, there will be nearly 3pF more capacitance added when connected to the DUT, safety hence is not guaranteed.

  • Wide Measurement Range

    Unlike traditional differential probes can only test high-voltage signals, SigOFIT probe can be used with different attenuator tips to test differential mode signals from ±1.25V to ±2500V, achieve full-range output and very high signal-to-noise ratio.

  • Efficient & Affordable

    Fastest response, can be tested immediately after power-on; AutoZero completed in less than 1 second, ensures accurate signal output in real time.

  • Applications

    *  Design of motor drive, power converter, electronic ballast

    *  Design of GaN, SiC, 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 & ESD troubleshooting

    *  Floating measurements

Model & Ordering Name








MOIP01P: 100MHz

MOIP02P: 200MHz

MOIP03P: 350MHz

MOIP05P: 500MHz

MOIP08P: 800MHz


Rise time

MOIP01P: ≤3.5ns

MOIP02P: ≤1.75ns

MOIP03P: ≤1ns

MOIP05P: ≤700ps

MOIP08P: ≤438ps

MOIP10P: ≤350ps

Output Voltage

MOIP01P/MOIP02P: ±2.5V


Differential Voltage Range




50X: ±62.5V

System noise (rms)


SMA Input Impedance

1MΩ || 10pF

Propagation delay

15.42ns (2m)

Power supply

USB Type-C, DC: 5V

DC Gain accuracy


Common mode voltage range


Fiber cable length

2m (Customizable)


0°C to 40°C (operating), -20°C to +70°C (non-operating)


5% to 85% RH (non-condensing), 75% RH above 30°C, 45% RH above 40°C


3000 m (operating), 12,000 m (non-operating)


Indoor Use Only

Package size

37*11*32.5 cm

Package GW


Main Machine

Module No. Item Description
MOIP01P Optical-fiber Isolated Probe SigOFIT 100MHz, 2-meter fiber cable
MOIP02P Optical-fiber Isolated Probe SigOFIT 200MHz, 2-meter fiber cable
MOIP03P Optical-fiber Isolated Probe SigOFIT 350MHz, 2-meter fiber cable
MOIP05P Optical-fiber Isolated Probe SigOFIT 500MHz, 2-meter fiber cable
MOIP08P Optical-fiber Isolated Probe SigOFIT 800MHz, 2-meter fiber cable
MOIP10P Optical-fiber Isolated Probe SigOFIT 1GHz, 2-meter fiber cable

Standard accessories

Module No. Description
MCX connector (2.54mm) *5 Connecting SigOFIT and the circuit under test
MCX connector (5.08mm) *5 Connecting SigOFIT and the circuit under test
MCX coaxial cable *1 Connecting SigOFIT and the circuit under test
Carrying Case *1 Case with EVA foam
Probe Mount *1 Bipod mount to support probe head
USB type-C to type-C cord *1 To power the Optical-Electrical Converter
25W USB charger *1 To power the Optical-Electrical Converter

Optional accessories

Module No. Description
OP10-x Attenuator tip of 10X
OP20-x Attenuator tip of 20X
OP50-x Attenuator tip of 50X
OP500-x Attenuator tip of 500X
OP1000-x Attenuator tip of 1000X
OP2000-x Attenuator tip of 2000X

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