Using 100x40mm as format I actually seem to be able to move all components top-side and still add caps on board. I am not sure about density around MCU yet, but this is one driver. The weak links are as always the current paths, but I think this will be ok for 15-25A. This is just a routing experiment and this will be ok under the assumption that I do not need a heat-sink. I do however have the option to replace the big red lane with a 1 or 2 mm wire and use hole though to bottom lane to vent the SOP Advance. In which case I can even mount heat-sink on bottom. All components on top means I can use bottom lane as ground plane as well. Lets see.

This is 25% larger than the same channel with components on 2 sides. I have several times been surprised of how little extra space I need to make components on one side only.

Also I realize how little extra that is needed to target 50A here, but lets see how we go on MCU area first.

The 40V or 30V or 26V – ouch limits have always annoyed me, so with new MOSFET’s, current sensors and PSU I change to 60V design. Making Space for SOP Advance I can always use SOP and 30V MOSFET’s anyway.

I finally found several temperature sensors in SOT23 package, so I ordered 2 different ones to test. SOT23 with no passive components means I should be able to sneak these in between the MOSFET’s – add 2 on MC4X.. and 1 one MC3P..

Testing MC4X I realize that I probably need to re-route revision 1.1 from scratch. I need a minimum of 1mm extra space between channels for SOP Advance package options + I want JST connectors on each channel rather than 1.27 pitch headers. I need space for INA194 as well as the temperature sensors. I also want 1000uF on the controller directly etc.

On the present controller I tried for a more narrow board and ended up adding space. Truth is that MC3P end up being a smaller design with components only on top side – I don’t think I can or want top-side only on MC4X, but I would like 100 x 40mm format due to the availability of heat-sink’s in that size. So if I include capacitors on that size it will be good.

I am not going to bother with higher currents on this solution as it would require to much. I got the 3P design for higher currents and 3-phase motors even if I realize that my first routing here also need to be modified.

It will be a bit of work before I order either MC4X or MC3P as both needs changes, but it is worth it. I am actually impressed with MC4X testing so far despite a few set-backs. I expected PCB lanes to be a problem and not dodgy MOSFET’s, so things are looking very good for a 15A design. With new MOSFET’s I might very well upgrade current ratings, but that is not an objective right now. I will also be using 3X-, 4X- and 3P-Controller as terminology from here. Writing the full names are a bit confusing and at present I only want to continue with 3 controllers. Others do small, insane 3-phase drivers better than me, so I focus on actuator Controllers. I can never compete With the smallest size using 2-layers anyway – but, it is real fun to see what I can achieve.

This shows my new driver circuit. I added R43 and R44 as weal pulldown’s to avoid that the MOSFET start leading by accident at power up. If I get space limitations I will rather remove R1 and R2. This will make it safer to put power on a Motor Controller in case the Gate Driver is disconnected or broken.

I still want to test more with rev 1.0 of MC4X24V15A, but I am also planning an upgrade. I initially drew a rev 1.1 using 78M12, but I will replace LMR14206 with TPS54x60 and AMS1117 with SPX3819. That will increase range to 60V which basically means 48V. I do have the challenge that I also want 12V and I need 12V on the Gate Drivers. The only solution I know of is by bypassing the DC/DC if input voltage is below 14V.

The supercap stays, that part of the design was really succesfully, but I need to consider if I need 5V as well for the Hall Sensors etc. In which case I need 4 voltages on the controller.

I will change to the new SWD to save some space + this should be better in this case as it won’t be in the way.

I will also change the connectors to JST Micro as I see little purpose in the larger ones.

I would like to find smaller diodes for the Gate Driver chargers.

I also consider dropping that cap add-on and get the caps directly on the board. Use 1000uF 16/35V in series etc.

INA210 will be replaced with INA194.

I need to test that Hall Sensor circuit and consider changing it.

Temp1 and Temp2 needs to be changed.

Resolver port can be removed.

And then comes the question about the MOSFET’s. IRF7862 is great, but some of the new ones are just in a different scale. 3.3mOhm versus 0.65mOhm is a huge difference as the later will allow much, much higher currents. But, if I make the footprint for SOP Advance a SOP-8 will also fit onto that. The only difference is the PAD on SOP Advance. I can even stick SOP Advance on SOP-8 with some care – I just do not get the advantage of the PAD’s heat dissipation. But, I do need to remove a place-through underneath the IRF7862. With this I can interchange MOSFET’s. New product name will be MC4X60V15A. I don’t plan on changing the 15A limit. MOSFET’s will take far more, but PCB lanes will start burning.

Returning a bit to MC3P60V50A I realize that I have done a few mistakes. Some of the smaller capacitors needs to be 60V+ and I need to put the main capacitor somewhere. All in all I might have to use a few more mm in width which is fine.

I am still waiting on PCB’s for MC3X3A. As for the micro one using DRV10983 I am actually considering ditching that one. It run’s the motor, but I am not impressed. After a while it heats up and misbehave. I tried a L293 just to compare and was more impressed by how easy it was to use this to run the same 3-phase motor. I liked DRV10983 over DRV8313, but – well – I will code it’s I2C interface and see what I can achieve.

Searching on Arrow’s pages I found 3 MOSFET’s in SOP Advance package that have insane ratings.

• 2.         40V 246A Rds=1mOhm 1.2 USD
• 3          45V 280A Rds=0.8mOhm 1.4 USD
• 3.         30V 280A Rds=0.65mOhm 1.3 USD

Actual limit is more like 150A with a pulse drain of 500A in accordance to datasheet. But, look at the RDS on that 30V MOSFET – 0.65mOhm. With a power dissipation of ca 1W as a hand-rule that means almost 40A without a heat-sink if my calculations are correct. Lets try them out!

I ordered 10 of these to test because they are very attractive for a 12V/24V design where you benefit from higher currents. I have no intention of even trying their datasheet limit as I am more interested in the range 15-50A which should be well within their capabilities.

FedEx has been nice and responsive and they basically told me how to avoid getting slammed with extra toll fee’s, so they are forgiven 🙂