3 Phase Controller V0.2 & V0.3

    After the moderate success of the version 0.1 build of the 3 phase controller, I got to work on the next iteration.  I was now confident enough to use an IC package with no leads.  The DRV8323R was the obvious choice after this development.  It can do everything that the DRV8203 can do (and more) in a smaller package.  The additional features include one more current sense signal amplifier (this can help with detecting a short or leakage current in a 3 phase motor) and the option between parameter setting via SPI or passive components.

This is the VQFN48 package

I came up with a list of improvements that I wanted to see in the board:

1. Get an assortment of resistors to change dead time with
2. Correct the spacing for the block terminal and THT capacitor footprints
3. Get rid of all thermal reliefs in the power part of the board
4. Design for greater current flow and heat dissipation
5. Use an XT-30 connector for power
6. Enlarge the phase holes
7. Breakout 3V3 for general purpose
8. Breakout GPIO pins for hall sensor reading
9. Get rid of soldermask over power bus to allow for soldering a copper plate onto it for increased current-carrying capabilities
10. 3mm holes at board corners for standoffs

All of these improvements made their way onto the new board except for those highlighted in red.  They will be added to a more mature version of the board.

    I ordered 5 boards for $5 (also includes shipping) and a week out from when they were supposed to show up, I went online to order the rest of the BOM.  When I had started designing the new board, I'm almost certain that I checked on 8323 availability and there were no issues.  However, a few weeks later, there were no individual ICs to be found.  With the silicon crisis still raging and TI's Richardson plant taking a hit earlier this year in the brownout, the 8323s were not a big focus compared to TI's bread and butter silicon packages.  Thus, I was kind of screwed.  Even now, months and months later, there is still a terrible shortage of chips in general.  My workaround was ordering some of the less popular gate driving chips and making them work.  Of course, what was available was not pin-to-pin compatible with what my boards currently were.  I was not about to bodge the shit out my beautiful board, so I fixed up the cad and ordered version 0.3 of the board.  The subsequent build is with that PCB and the DRV8353.

Finally using the Invention Studio's pre-heater; not sure if I could handle this lead-less package without

Messed up my solder mask on a single pad in the bottom left

After the mask was scraped off, it took solder pretty well

...though not perfectly

I had a terrible time lining this guy up even though several sourced claimed it would flow into place on its own

Package melted a bit on the far side after I let a fine solder tip linger a bit too long

Failed attempt at trying to tin the pins

Finally situated and looking alright after copious amounts of solder flux

Back to the phone camera

Two half h-bridges soldered on

Board mostly populated and buck converter works!

Nucleo board soldered to the controller shield

    This is the current form of the motor controller as of now.  The next steps are to get the hardware running and develop a mature embedded system with which to control the motor and take commands from a command line interface running on Linux.