TIDA-01063: TIDA-01063

Hello Harshit, i hope all is well, thank you for contacting us.

in the design files for TIDA-01063, you will find schematics and layout for the signal conditioning circuit and only layout for PCB Rogowski coil. the layout for PCB Rogowski contains traces and vis, no passive or active components, thus no need for schematics. 

please don't hesitate to reach out if you have any questiond.

best regards,

Danny 

SEM | E-meters 

Thank you for your response and clarification.

I had a follow-up question — instead of using a full Rogowski coil, I’m exploring the possibility of designing a half coil for my application.

Could you please let me know if this is feasible? If yes, I would appreciate any guidance on the design considerations or limitations I should keep in mind while implementing a half Rogowski coil based on your reference design.

Looking forward to your suggestions.

Best regards,
Harshit Kumar Shakya
Hardware Design Engineer

Hi Harshit,

Thank you for your follow-up question. Could you please clarify what you mean by a “half coil” in this context? Are you referring to physically using only part of the winding, or a specific mechanical layout constraint for your application?

Additionally, it would help to understand more about your target application and the constraints driving this design choice—this will allow me to provide more tailored guidance.

In general, I would suggest considering differential routing instead of single-ended to help maintain signal integrity, EMI immunity, and parasitic capacitance elimination. Also, please be mindful that any gaps or discontinuities in the coil will introduce distortion and non-linearity in the output signal, which can impact measurement accuracy.

Looking forward to your details so I can better advise you.

Best regards

Thank you for your reply.

To clarify, by “half coil,” I meant a semi-circular PCB layout. Due to mechanical constraints, I’m planning to use two identical semi-circular coils placed around the conductor to work together like a full Rogowski coil.

I will ensure both sections have the same number of turns, proper winding direction, and are connected in series. Differential routing and shield grounding will also be considered to maintain signal quality.

I would really appreciate any guidance, design tips, or things to watch out for in this kind of implementation. Your suggestions would help me a lot in making the design more reliable and accurate.

Looking forward to your support.

Best regards,

Hello Harshit, 

thank you for clarifying the design. couple of things to watch out for, PCB manufacturers have a limit on how close you can place your vias and traces to the edge of the PCB. Now, this constraint will create gaps between your semicircular PCB Thus, will cause distortion of the output signal of Rogowski coil.

Another possible solution to consider if you're constrained in size and form factor, you can make a full circular PCB Rogowski, decrease it's surface area to fit in your design and stack multiple coils together in series to multiply your sensitivity. you can also compensate for the low amplitude signal with gain amplifier, for example, you can use the INA333 as gain amplifier. 

Keep in mind that Rogowski coil is a di/dt sensor and the output signal is a proportional voltage to the current. Rogowski's output must be integrated (HW or SW) to get an accurate current waveforms. because Rogowski coil is a di/dt current sensor, when the waveforms crosses zero, the output of the coil will be distorted, i don't think that there is a way around this. However, zero crossing distortion is not significant. 

please don't hesitate to reach out with any questions.

Best regards, 

Thank you for your detailed feedback and helpful suggestions.

We’ll make sure to review the PCB edge clearance constraints and adjust the via and trace placement accordingly to avoid any signal distortion caused by gaps between the semi-circular PCBs.

We will also look into the full circular Rogowski design with reduced area and evaluate the option of stacking coils in series to improve sensitivity. The INA333 amplifier recommendation is appreciated — we’ll consider it for signal conditioning in our design.

As you mentioned, we'll ensure proper integration of the Rogowski output to reconstruct the current waveform accurately, and we'll keep the minor zero-crossing distortion in mind during evaluation.

Thanks again for your support. I’ll reach out if we need further clarification.

Best regards,
Harshit Kumar Shakya

Hello Danny,

Thank you for your feedback on the Rogowski coil design. We’ll implement the suggestions regarding edge clearance and signal amplification.

I understand you have your test system, but could you please suggest how I can custom-build a small setup just for basic testing? Any minimal circuit, block diagram, or guidance for checking the coil output would be very helpful.

Looking forward to your suggestions.

Best regards,
Harshit Kumar Shakya

hello Harshit, i hope all is well

thank you for reaching out, i would recommend for a test setup: clamp current meter, current probe, passive prove, conductor with current flow (AC), and an oscilloscope. you can see the output Sin wave from the output of the Rogowski coil using the passive prove on the scope, for accuracy and sensitivity measurements, connect the current probe to the conductor and compare pk-pk values to calculate sensitivity. once you have that number you can use it for signal condition circuit design. 

please don't hesitate to reach out if there are any further questions 

Best regards, 

Danny  

Thank you for your continued support.

I’d like to ask if it’s possible to test the Rogowski coil output using a multimeter, or is an oscilloscope strictly required for meaningful results? If multimeter testing is feasible, could you kindly share the basic setup, expected readings, and any related calculations?

If you have any reference videos or documentation, that would be very helpful for me to better understand the process.

Looking forward to your guidance.

Best regards,
Harshit Kumar Shakya

Hello Harshit, i hope all is well

Thank you for your question.

Yes, it is possible to use a multimeter to test the output of a Rogowski coil, but there are important limitations to keep in mind. Rogowski coils—especially PCB-based designs—typically have very low sensitivity. For example, if your coil has a sensitivity of 100 µV/A and you’re running 100 A through the conductor, the output would only be about 10 mV. Many standard multimeters are not precise enough to accurately read such low voltages.

Additionally, most multimeters display RMS values, whereas Rogowski coils output a voltage proportional to the rate of change of current (di/dt), which means the waveform is typically sinusoidal (if the current is sinusoidal), and peak-to-peak measurements are more meaningful when calculating sensitivity. To obtain accurate results, you would need to either:

• Convert the RMS reading to peak or peak-to-peak (multiply by √2 or 2√2, respectively), and

• Ensure your multimeter has sufficient resolution (ideally in the microvolt or low millivolt range).

For meaningful signal analysis, especially for waveform shape or phase information, an oscilloscope is strongly recommended. It will allow you to visualize the actual output waveform, assess signal integrity, and directly measure peak or peak-to-peak voltages.

Basic setup if using a multimeter:

1. Pass a known sinusoidal AC current (e.g., 50 Hz, 100 A) through the conductor.

2. Connect the Rogowski coil output to your multimeter (ensure it’s set to AC voltage mode).

3. Take the reading and compare against expected voltage (Current × Sensitivity).

4. Convert RMS reading to peak-to-peak if needed: Vp-p = Vrms * 2* sqrt(2)

Let me know if you need help interpreting any results or selecting the right oscilloscope probe or instrumentation amplifier.

Best regards

Thank you for the detailed explanation and guidance.

We’re planning to use Fluke 117 and Fluke 15B+ multimeters for initial testing. Based on their specifications, do you think they would offer sufficient resolution and accuracy for meaningful readings from the Rogowski coil?

Looking forward to your input.

Best regards,
Harshit Kumar Shakya

I think that your teste equipment will be sufficient enough. However, i would recommend using a filter and a gain amplifier at the output of your coil, doing this will allow you to get good accuracy measurements. keep in mind, if you implement a filter and an amplifier, you would need to factor in gain and attenuation of the filter to your calculation.

I*S*(G-AF)=Vo

I = input current 

S = sensitivity of the coil 

G = gain 

AF = attenuation factor measured in db (need to convert to V/V) AF,V/V = 10^(db/20)

Vo = output voltage

Let me know if you need help picking a filter and an amplifier for your design.

best regards, 

Danny