Serious FOCer (84V VESC 6 based controller)

[shaman]

IRFP4468 is not expensive from lcsc.

I appreciate the feedback here. Yeah FET replacement would be difficult. It's just hard to pass up those juicy specs. I've looked at the IRFP4468. The only problem with that is the typical total gate charge is high and rides the upper limit of the DRV for 20kHz switching frequency. The max gate charge exceeds the limit. You could use this in my FOCer but 15kHz switching frequency would have to be the max.

The IRF100P219XKMA1 seems to be a good alternative with about half the gate charge. Price is higher though.

https://www.mouser.com/ProductDetail/Infineon-Technologies/IRF100P219XKMA1?qs=%2Fha2pyFadug%252B6wavJZPX4Q5gIlLGNGBj6P7x7AfWN1qOUY2YSSk6PQKxcfpfQmxB&utm_source=octopart&utm_medium=aggregator&utm_campaign=726-IRF100P219XKMA1&utm_content=Infineon

 

[spinningmagnets]

Replacing a mosfet was an absolute nightmare though. Need a lot of heat with all that copper

You might consider trying out a resistance soldering unit / RSU. I don't know if the AC current would hurt a mosfet.

 

[nieles]

IRFP4468 is not expensive from lcsc.

The IRF100P219XKMA1 seems to be a good alternative with about half the gate charge. Price is higher though.

https://www.mouser.com/ProductDetail/Infineon-Technologies/IRF100P219XKMA1?qs=%2Fha2pyFadug%252B6wavJZPX4Q5gIlLGNGBj6P7x7AfWN1qOUY2YSSk6PQKxcfpfQmxB&utm_source=octopart&utm_medium=aggregator&utm_campaign=726-IRF100P219XKMA1&utm_content=Infineon

that is one hell of a MOSFET! WOW!! nice find.

 

[shaman]

consider trying out a resistance soldering unit / RSU

I'll have to look up what that is.

that is one hell of a MOSFET! WOW!! nice find.

Thanks yeah it's my prospect TO-247 FET for the respective version of FOCer. Anyone know the max practical current a TO-247 can handle assuming really good heatsinking? I'd like to give a more accurate prediction of the max power rating for the TO-247 FOCer.

 

[spinningmagnets]

RSU...

https://www.electricbike.com/resistance-soldering-unit/

 

[nieles]

for so long i have this idea in my head to use an aluminium PCB for the heat sink interface. this could be an awesome project to try this!

because aluminium PCB has awesome heat conductivity and still has electrical isolation.

so the idea is pretty simple. just design a small pcb with only one pad to solder the mosfet to, and two holes to attach the aluminium PCB to the actual heat sink. normal thermal compound can be used here. added benefit is that there will be a larger surface area to add thermal compound to, resulting in more heat transfer.

 

[shaman]

@spinningmagnets

hmmm...I'm not sure about running active current in the power stage of a controller in order to solder. That current may flow somewhere it's not supposed too. This works similar to a welder or spot welder as mentioned in the article. Examples of use tend to be joining large bodies of metal together and not on sensitive electronics unless I missed something.

 

[shaman]

aluminium PCB for the heat sink interface

Where do you get these made?

 

[district9prawn]

Replacing a mosfet was an absolute nightmare though. Need a lot of heat with all that copper

You might consider trying out a resistance soldering unit / RSU. I don't know if the AC current would hurt a mosfet.

The first repair I blasted with the heat gun and ended up killing a current sense amplifier. Second time I gently preheated the board, then removed the bars with soldering iron then hit the bad part with the hot air. Things go much better when you use your brain :wink:

I really hope the 100v drv turns out more reliable than the 60v ones.

 

[shaman]

I really hope the 100v drv turns out more reliable than the 60v ones.

That's the idea here. More headroom for more reliability. The users of the 60V VESCs tend to run it with 12s batteries. That doesn't leave much margin for transients and there are many cases of people blowing up their VESCs like this. Also e-skaters tend to not expose their ESCs to air for some reason. They just throw it in a plastic enclosure underneath the board and hope for the best.

 

[neptronix]

It's been a long time since i've got excited about controllers. I'm still running oldschool infineon clones mainly.
I like what you're doing here and look forward to one day, finding something better than my ol' trapezoidal drives.
Subscribed so i can stalk your updates.

 

[shaman]

@neptronix

Thanks and happy stalking!

 

[nieles]

aluminium PCB for the heat sink interface

Where do you get these made?

https://www.pcbway.com/orderonline.aspx

47 dollar for 100 aluminium pcb (20mm by 25mm)

there are a few other Chinese PCB manufacturers that offer Proto aluminium pcb. if i remember correctly i saw an ever cheaper option, but cant remember the name.

 

[shaman]

I think at that price point I would just go with Aluminum Nitride insulators

https://www.aliexpress.com/store/product/ALN-Insulator-Cooling-Pad-TO-247-0-635mm-17mm-22mm-Aluminium-Nitride-Ceramic-With-Hole/1768062_32864266729.html?spm=2114.12010612.8148356.4.70ae2b63vxb6Nm

Aluminum Nitride still has really good thermal conductivity

 

[John in CR]

IRFP4468 is not expensive from lcsc.

The IRF100P219XKMA1 seems to be a good alternative with about half the gate charge. Price is higher though.

https://www.mouser.com/ProductDetail/Infineon-Technologies/IRF100P219XKMA1?qs=%2Fha2pyFadug%252B6wavJZPX4Q5gIlLGNGBj6P7x7AfWN1qOUY2YSSk6PQKxcfpfQmxB&utm_source=octopart&utm_medium=aggregator&utm_campaign=726-IRF100P219XKMA1&utm_content=Infineon

that is one hell of a MOSFET! WOW!! nice find.

??? Rds on 1.7 ohms gotta be mohms, right?

 

[nieles]

IRFP4468 is not expensive from lcsc.

The IRF100P219XKMA1 seems to be a good alternative with about half the gate charge. Price is higher though.

https://www.mouser.com/ProductDetail/Infineon-Technologies/IRF100P219XKMA1?qs=%2Fha2pyFadug%252B6wavJZPX4Q5gIlLGNGBj6P7x7AfWN1qOUY2YSSk6PQKxcfpfQmxB&utm_source=octopart&utm_medium=aggregator&utm_campaign=726-IRF100P219XKMA1&utm_content=Infineon

that is one hell of a MOSFET! WOW!! nice find.

??? Rds on 1.7 ohms gotta be mohms, right?

LOL yeah mOhm

 

[shaman]

??? Rds on 1.7 ohms gotta be mohms, right?

Yeah Mouser must have messed up on that. The datasheet has it right...hopefully

 

[maxxximatoze]

TO247.jpg
TO-247 version

12 FET angled.PNG
vertical 12 FET TO-220 version

12 FET with Sink angled.PNG
vertical 12 FET TO-220 version w/aluminum channel heatsink

12 FET with Sink side.PNG
vertical 12 FET TO-220 version w/aluminum channel heatsink

6 FET angled.PNG
vertical 6 FET TO-220 version

TO220 horizontal.jpg
horizontal TO-220 version. Image for reference only. Layout does not yet accommodate horizontal TO-220 package.

Announcing the Serious FOCer (working title)

Features:

• 15V to 84V operation

• Expected power of approx 5kW with TO-247 FETs and good heat sinking

• Has primary features of VESC controllers (FOC, configurable current/temperature limits, throttle response, dual motor operation, ect.)

• Different versions for different FET packages

• TO-247 version for higher current capability

• Single-sided dual-layer PCB

• Small 45mm x 101.5mm board size

• Each switch node has it's own bulk cap, pwr, gnd and phase cable holes. Reduces need for beefing up long traces for increased current handling capability

• Utilizes DRV8353RS to achieve higher operating voltage, superior fault detection, and small footprint. Also allows for tailored slew rate control to minimize ringing/spiking in the power stage

• Easy On/Off capability with switch of choice

• Wireless Bluetooth transceiver module can be easily added for wireless interface with VESC Android App. Allows for easy configurations of different speed/power profiles that can be selected at will.

• Design will be open sourced after verification

• Designed in KiCAD for flexibility and compatibility with the open source community

Donations:
Open Source R&D isn't free! Any help is appreciated!
https://www.paypal.me/shamansystems?locale.x=en_US

This is the higher performing controller in comparison to my Cheap FOCer controller that is about to go into beta testing. All lessons learned from the Cheap FOCer development has and will go into this new controller design. I am open to any suggestions that will help make this controller great for this community!

It's seems to be a bit excessive for the voltage rating at 84V because the DRV8353R is good for 75V max recommended in the datasheet, unless the supplied voltage is reduced just for the DRV8353RS (and let the mosfet at 84V), but I could be wrong.

Where do you think you will put the decoupling caps on the board, can it work without ?

And what do you think about using TVS diodes to protect the DRV8353R against negative transient (like in the infineon 2EDL23x06PJ driver family) ?

And what do you think of connecting the thermal pad of the DRV8353R to a big ground plane on the back side of the PCB with through holes via to help to keep it cool and stable ?

How do you accurately measure the mosfet temp ?

No more question sir !

 

[shaman]

@maxxximatoze



The DRV8353RS has a 100V max for the driving the power stage. Only VM has the limit of 75V. VM is actually fed 15V by the buck converter in the design. There is TI documentation on running the DRV8353RS in this configuration.

The large decoupling caps aren't 3D modeled but they have a white outline in the images for the horizontal orientation. There are 3 of them. 1 100V 470uF per switching node.

The slew rate control is there to prevent transients in the first place. TVS diodes may still be good for added protection.

Yes the thermal pad is already connected to a large ground plane on the bottom layer. This is standard practice for all ICs that have thermal pads underneath.

MOSFET temp is measured by a 1% 10K NTC kapton taped the FET package. I did this for my Cheap FOCer controller.

 

[maxxximatoze]

@maxxximatoze

Capture.JPG

The DRV8353RS has a 100V max for the driving the power stage. Only VM has the limit of 75V. VM is actually fed 15V by the buck converter in the design. There is TI documentation on running the DRV8353RS in this configuration.

The large decoupling caps aren't 3D modeled but they have a white outline in the images for the horizontal orientation. There are 3 of them. 1 100V 470uF per switching node.

The slew rate control is there to prevent transients in the first place. TVS diodes may still be good for added protection.

Yes the thermal pad is already connected to a large ground plane on the bottom layer. This is standard practice for all ICs that have thermal pads underneath.

MOSFET temp is measured by a 1% 10K NTC kapton taped the FET package. I did this for my Cheap FOCer controller.

It's perfect, I give you a A+ ! can't wait to see the result of this cheap, compact AND beefy bad mother FOCer !

Do you have an idea for an aluminium case to put the beast in ?

 

[shaman]

Thanks! The Hammond 1590N1 (125b) for the 6 FET versions and the 1590BB for the 12 FET version. They're easy to come by. Also your generic extruded aluminum enclosures will work fine too.

 

[maxxximatoze]

Thanks! The Hammond 1590N1 (125b) for the 6 FET versions and the 1590BB for the 12 FET version. They're easy to come by. Also your generic extruded aluminum enclosures will work fine too.

Is this case will fit the to-247 version or just the to-220 one ?

 

[shaman]

It should accommodate either as the 1590N1 (125b) inside height is 35mm.

 

[maxxximatoze]

It should accommodate either as the 1590N1 (125b) inside height is 35mm.

What TO-247 do you plan to use in you design ? Do you know the very good and not too expensive TO-247 infineon IRF100P219 (1.4milliohms at 100V) ? Maybe you could also plan a 12xTO-247 (the IRF100P219 does not have a huge gate charge, maybe possible to drive 12 instead of 6) ? It woul be an absolute little monster !

 

[shaman]

Yes that's the one I've looked at to use. I've already mentioned that in this thread.

I agree that a 12 TO-247 is possible. It would just be a bit expensive. You're right that the energy output would be big for it's size. I may design one anyway.