Cherry Blossom vs CELUS: a CELUS alternative

Two things in CELUS's own materials are worth knowing before you commit. The first is the account terms: a free Community Account makes your projects and uploads public, and keeping them private means a Professional subscription paid upfront for twelve months, at a price the site does not publish. The second is where the work stops. CELUS delivers a reference schematic and BOM, and someone still has to lay out the board in an EDA tool.

If your design has to stay private without a year's commitment, or there is nobody on hand to do the layout, those are the gaps to fill. Cherry Blossom fills both, which is why startups and makers without a layout engineer use it.

It can, and this board shows how. An AI agent built this 9 to 24 V in, 5 V at 3 A supply with tscircuit, the open-source engine Cherry Blossom runs on, on our own machine and with the same version and review tool Cherry Blossom's agent uses. The spec asked for a synchronous converter. On LCSC, the 60 V synchronous parts at this current come in a WQFN-30 package with a 0.5 mm pin pitch, which the board's 0.5 mm power traces cannot land on. So the agent used a non-synchronous TPS54360B with an external catch diode. Estimated full-load efficiency is 87% at 24 V, instead of the low 90s.

Stock shaped the values too. The timing equation lands on about 161k, and the nearest 162k resistor had only 1 to 17 in stock, so the board uses 160k and switches at 605 kHz. TI's example feedback pair was just as thin, so a 105k and 20k pair sets 5.000 V. All 36 placed parts have LCSC numbers.

When the schematic and BOM are finished before layout starts, a package problem like the first one lands on whoever does the layout. Here it came back as a part change before any files went out. One check is still yours: confirm the 3.3 V regulator (LCSC C500795, 640 in stock when reviewed) is still available before you order. An outside review also found that the supervisor chip, APX809, is marked not recommended for new designs, so plan a successor.

• You want a routed board and Gerbers, not a schematic you still have to lay out.

• You do not have a professional EDA tool to hand the schematic to.

• You want monthly billing rather than an annual commitment.

• You want to order the board from the same place, through the PCBWay hand-off.

CELUS gathers requirements by asking you questions. Cherry Blossom takes them in your own words, so start by writing down what the board has to do and sending that as your first message. The agent drafts the schematic and layout, and you refine it in the same chat. If your team later wants to finish the board in its own EDA tool, the KiCad export is an editable project.