USB-C Breakout and 3.3V Regulator Building Block Board — Part 2

USB-C Breakout and 3.3V Regulator Building Block Board — Part 2#

The first test batch of my 3.3V Regulator Building Block Boards arrived from JLCPCB today.

For this board, I used both JLCPCB’s PCB manufacturing service and their PCBA service to populate and solder the SMT components. This reflects a small change in my workflow: I am trying to focus more on design, documentation, testing, and repeatability, rather than hand-assembling every prototype in the workshop.

That is also why I approached this board with manufacturing and repeatability in mind from the start.

For these building block boards, my intention is to leave most through-hole components, such as pin headers and connectors, unpopulated. This gives me — and any future users of the boards — more flexibility when deciding how the board should be used. For example, 2.54mm pin headers could be soldered facing downwards for breadboard use, or upwards for integration into a larger project.

Fine-pitch connectors and SMT components are the exception, since those are usually better handled during assembly.

The order was originally placed on 2026-05-02 and arrived today, 2026-05-12, giving a total turnaround time of 10 days. For the kind of small manufacturing runs I am likely to place, that is quite reasonable — effectively less than two weeks from order to delivery.

My plan is to keep a small local stock of these prototype boards, without overstocking them before I have a better sense of demand. Longer term, I would also like to be able to manufacture standard or custom variants of these building block boards for customers who need something tailored to their own project — much like the software systems I also develop.

The JLCPCB delivery arrived via DHL Express in a simple blue cardboard box with the JLCPCB logo printed on the top. The order was well packed, with each assembled PCB wrapped in anti-static ESD bubble wrap. The boards were also separated with additional bubble wrap and wrapped into a roll. Nothing appeared to be under stress, and the PCBs arrived in good condition.

It is always a kick seeing something you have designed come back as a manufactured board.

I will likely keep four of these boards for the workshop and use one for stress testing. Over the next day or so, once some suitably bulky power resistors arrive, I plan to load-test one of the boards to document its failure mode and get a better feel for the current-handling ability of the design.

I did, however, carry out some basic checks before powering the board for the first time. This mostly involved checking for obvious shorts around the connectors and power rails. Looking at the high-resolution photo I took later, I probably did not need to worry too much, but it is still a useful habit to maintain.

After those checks, I powered the board and confirmed that it was producing the expected output voltage. The LED also turned on, which is always a pleasing little sign of life.

So far, I have tested the board with resistive loads drawing approximately 50mA and 100mA from the 3.3V output. Both tests were uneventful, with no obvious stability issues and no noticeable heat.

The more interesting results will come from testing at higher loads, particularly around 500mA, 750mA, and possibly 1A. Those tests should give me a better feel for the practical current-handling ability of the board, and where the thermal limits of this design start to become visible.

So far, so good.

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