Questions about SpeedVal Kit

NP1981

Hi, I am interested in purchasing the SpeedVal kit, but have a few questions about it before I buy:

1)     What is the maximum rms power that this platform can be used for? My understanding is 36kW (900Vmax x 40Amax). Is this correct? I intend to use it at 650V and 1.6A at 300KHz.

2)     How can I setup the safety enclosure shown in the DPT video that turns off the power to the kit if the lid is opened?

3)     I am interested in C3M0350120J, which comes in TO-263-7 package. However, the closest available power daughter card comes with C3M0075120J. Since they are footprint compatible, can I request to replace the C3M0075120J in the MOD-PWR-MM-C3M0075120J power daughter card with C3M0350120J?

4)     What is the maximum switching frequency of the PWM signal that I can inject into the daughter card? Is there a guideline for input signal frequency to fs ratio? I plan to inject a 300KHz signal at the input. What should be my switching frequency?

5)     Do you sell power daughter card in full bridge configuration?

6)     I am interested in using ADuM4146 gate driver card. In ADI’s UG, it says under “Equipment needed” that I would need the CGD12HB00D (2-Channel Differential Transceiver Companion Tool) for this gate driver card. However, I am not clear how to connect this tool in my test setup. Is this tool needed if I buy the SpeedVal kit and AduM4146 gate driver card?

Thanks,

Noman

TBhatia

Hello, thank you for your message. A member of our technical team is looking into your questions and we will respond shortly. 

Julius_R

DPT enclosure drawing.pdf

DPT Wiring sketch.docx

1)     What is the maximum rms power that this platform can be used for? My understanding is 36kW (900Vmax x 40Amax). Is this correct? I intend to use it at 650V and 1.6A at 300KHz.

There is no maximum power rating for this platform as the circuit maximum power capacity is highly dependent on switching frequency. The maximum voltage and current ratings are fixed due to the voltage and current sensing circuits and spacings that the board is designed to safely operate at. If you use one of the optional control boards, they have a max frequency of 150khz. They are not required and you can use your own function generator if you wish to run at higher frequencies than 150khz.

2)     How can I setup the safety enclosure shown in the DPT video that turns off the power to the kit if the lid is opened?

We use an Acopian high voltage, low current power supply (model P01.5HP40 & P02.5HP24) which have an inhibit terminal that disables the power supply if the inhibit terminal is pulled to ground. We use this terminal with an interlock that senses when the lid of the acrylic enclosure is open to disable the power supply anytime the lid is opened. There is a circuit with power resistors that are immediately placed across the DC bus when the enclosure is opened to rapidly discharge any voltage present. I am uploading a sketch of the wiring for this circuit as well as the drawing for the acrylic safety enclosure that we use. If you need the step file for the enclosure, we can email it you.

3)     I am interested in C3M0350120J, which comes in TO-263-7 package. However, the closest available power daughter card comes with C3M0075120J. Since they are footprint compatible, can I request to replace the C3M0075120J in the MOD-PWR-MM-C3M0075120J power daughter card with C3M0350120J?

For immediate testing, you could purchase the C3M0075120J power daughtercard and simply desolder the two MOSFETs and replace with two C3M0350120J devices. The current waveforms might contain significant ringing as we tune the current sense resistors and filter compensation network for each card individually based on the populated MOSFET's characteristics. The C3M0350120J is a significantly lower current device than the C3M0075120J so the current sense resistors might not be optimal. You can certainly still perform testing and the board should work fine, but be wary that your current measurement waveforms might not be optimal. We plan to eventually release power daughtercards for each of our C3M MOSFETs with optimized current sensing but the C3M0350120J has not been released yet.

4)     What is the maximum switching frequency of the PWM signal that I can inject into the daughter card? Is there a guideline for input signal frequency to fs ratio? I plan to inject a 300KHz signal at the input. What should be my switching frequency?

We don't have a maximum switching frequency for the Speedval kit; however, the optional controller cards will support a maximum switching frequency of 150khz. You could use your own function generator to produce higher pwm frequencies.

5)     Do you sell power daughter card in full bridge configuration?

Currently, we only have Speedval half bridge power daughter cards.

6)     I am interested in using ADuM4146 gate driver card. In ADI’s UG, it says under “Equipment needed” that I would need the CGD12HB00D (2-Channel Differential Transceiver Companion Tool) for this gate driver card. However, I am not clear how to connect this tool in my test setup. Is this tool needed if I buy the SpeedVal kit and AduM4146 gate driver card?

If you purchase the ADum4146 gate driver card, you don't need to purchase anything else. The Speedval kit will contain everything you need to get up and running with the ADuM4146 driver card.

NP1981

Thanks Julius! I have a few more questions:

1) In the Motherboard user guide, supported power topologies shown are buck and boost converters. I am actually working on the design of an AC to DC converter. Do you think I can perform some half-bridge rectifier testing using this kit?

2) I am tasked with designing an AC to DC converter that can take a 300KHz AC signal having rms voltage of 650V and rms current of 1.6A and convert that to ~650V DC voltage at the output. Does Wolfspeed have an eval board or reference design that I can look at as reference/guidance to come up with my own design?

Best Regards,

Noman

Julius_R

We are a little confused by some of your requirements and trying to understand the circuit better so that we can advise you. It would be helpful if you could post a sketch of your circuit and explain the circuit a little more. If you don't want to post the circuit here on the public forum, you are welcome to direct message us so we can advise further.

NP1981

Can you share your email address so I can explain better over email?

TBhatia

Hello Noman,

The team has already reached out to you via email so I will close this discussion for now but if you have a follow up question, please "Start a New Discussion" and we would be glad to support you further.