EEVblog 1557 – Micsig SigOFIT Optical Fibre Probe + GaN Experiment

Review of the new Micsig SigOFIT Optical Fibre oscilloscope probe, including a practical demonstation of the incredible CMRR range of opticallly isolated probing of a 300V GaN transistor driver circuit.
And a direct comparison with the HVP-70 high voltage differential probe to show you the incredible game changing difference optical fibre probes make.

https://www.micsig.com/SigOFIT/

CMRR Explained video: https://www.youtube.com/watch?v=vDe_BHvRpks

Forum: https://www.eevblog.com/forum/blog/eevblog-1557-micsig-sigofit-optical-fibre-probe-gan-experiment/

Links:
https://www.infineon.com/dgdl/Infineon-1EDF5673K-DataSheet-v02_04-EN.pdf
https://www.infineon.com/dgdl/Infineon-ApplicationNote_CoolGaN_600V_emode_HEMTs_-Driving_CoolGaN_high_electron_mobility_transistors_with_EiceDRIVER_%201EDI_Compact-AN-v01_00-EN.pdf
https://www.infineon.com/dgdl/Infineon-ApplicationNote_CoolGaN_600V_emode_HEMTs-AN-v01_00-EN.pdf
https://www.infineon.com/dgdl/Infineon-ApplicationNote_EvaluationBoard_EVAL_1EDF_G1_HB_GAN-ApplicationNotes-v01_03-EN.pdf
https://www.infineon.com/dgdl/Infineon-GalliumNitride_CoolGaN_emode_HEMTs-ProductSelectionGuide-v01_01-EN.pdf
https://www.infineon.com/dgdl/Infineon-IGOT60R070D1-DataSheet-v02_14-EN.pdf
https://www.infineon.com/dgdl/Infineon-ProductBrief_GalliumNitride_CoolGaN_600V_e-mode_HEMTs-ProductBrief-v03_00-EN.pdf
https://www.infineon.com/dgdl/Infineon-SolutionBrief_CoolGaN_and_GaN_EiceDRIVER-ProductBrief-v01_00-EN.pdf
Demo board: https://www.digikey.com/en/products/detail/infineon-technologies/EVAL1EDFG1BHBGANTOBO1/13548558

00:00 – Micsig SigOFIT Optical Fibre Probe vs Active FET
02:25 – High Voltage Differential Limitation and why you might need an Optical Fibre probe
03:25 – Galvanically isolated, and power-over-fibre
04:39 – Comparison with the Tek IsoVu & Lecroy DL-ISO
05:55 – The CMRR is AMAZING!
07:15 – A look at the SigOFIT probe
10:04 – An optical fibre probe is NOT a high voltage differential probe!
10:40 – Practical example using a 600V Gallium Nitride GaN circuit demo
11:39 – What is a Gallium Nitride (GaN) Transistor?
13:23 – GaN / HEMT, and Silicon Carbide SiC Transistors
14:21 – IGOT60R070D1 600V GaN datasheet & Half Bridge switching configuration
15:30 – This is IMPOSSIBLE with a regular probe!
19:07 – GaN EiceDRIVER chip
19:54 – The practical GaN test setup
23:10 – Remote MXO4 scope control to take measurements
24:36 – High side GaN power transistor measurement with the SigOFIT
26:26 – Here is where the CMRR MAGIC happens!
27:41 – Comparison with HVP-70 High Voltage Differential Probe
28:45 – Look how the High Voltage Differential Probe is just horrible here!
31:56 – Baseline High Voltage Differential probe ringing vs SigOFIT
32:21 – Noise measurement
36:27 – Conclusion

Podcast: Download