12 V to 5 V / 1 A Buck Molecule (TPS54202)

@@ -1,85 +0,0 @@-# The process video: how it was made--The video on the [main page](https://wiki.adom.inc/john/buck-12v5v-molecule) tells this board's story start to finish: the prompt in Adom Hydrogen, the circuit, the three-engine simulation, the live layout in KiCad, the current and heat analysis and the rework it caused, the silkscreen, the part models, their pages on the Adom wiki, and what it cost. Every frame is real footage or a native render from this project.--- 4 min 0 s, 1080p, 30 fps, narrated from just after the logo appears to the last second, with subtitles burned in so it also works muted.-- It opens and closes on the dark Adom logo sting from [adom/adom-video-brand](https://wiki.adom.inc/adom/adom-video-brand).-- [Download the 1080p copy](docs/video/buck-process-v6-1080p.mp4). The player on the main page is a 1600 px web copy.--## Thumbnail--![The video's thumbnail: "Claude built this." with an arrow to the board's 3D render over a real Hydrogen screenshot](docs/video/buck-process-thumbnail.png)--1280 x 720, used as the player's poster and for YouTube. Built from the project's own pieces: a real Adom Hydrogen screenshot from the closing take, the board's 3D render from its GLB, the Adom logo, Familjen Grotesk and the brand gradient.--## Scenes and the footage behind them--Each scene is seen through a slow, eased camera move, and long recordings are sped up to their action. A scene is as long as its narration plus a short lead-in and tail; scenes cross-dissolve. All 3D shots are rendered frame by frame from the models, so they are smooth and free of cursors and browser chrome.--| starts at | scene | footage |-|---|---|---|-| 0:00 | Logo sting | The dark Adom intro sting. Its sound fades out as the narration comes in, 1.8 s in. |-| 0:04 | The prompt | The prompt typed into a real Claude Code thread in Adom Hydrogen, filmed with Adom Bridge's window recorder. It opens on a full shot of Hydrogen, then pushes in on the composer. |-| 0:15 | Opening | A smooth orbit of the finished molecule, rendered frame by frame from its GLB (etched parts, green D1, copper pads, rounded corners). |-| 0:30 | The circuit | The cleaned-up KiCad schematic, explored by an eased camera move. It stops on U1, whose symbol carries the TPS54202's chip outline in its body, then on C1, L1 and D1, which keep their standard symbols with a small 3D outline beside each. adom-symbol and adom-lbr made those drawings from each part's STEP model, on Adom's OpenCascade service. |-| 1:00 | Simulation | Filmed in Adom Hydrogen: a Claude thread on the left asks for an ngspice run, and the Adom SPICE dashboard in the webview on the right runs it live, then shows all three engines' overlays agreeing. Between those, LTspice and then PSpice for TI pop up over Hydrogen while their plots draw in. These two shots are composites: the LTspice and PSpice window footage comes from the [adom-spice skillpack](https://wiki.adom.inc/adom/adom-spice-skillpack) recording of the same dashboard (a Windows host driven by Adom Bridge), laid over a real Hydrogen take, because the Windows SPICE host was offline for the re-shoot. Vendor run times hidden (licence). |-| 1:28 | Placement | First run, placement clip: the AI placing 24 parts in KiCad 10, at 2.3x. |-| 1:41 | Routing and pours | Rework run: the routed traces with the pours stripped back, then the pours flooding back in. Then KiCad 10 on a second PC, driven by the Adom KiCad Bridge, selects one net at a time in the order the narration names them: GND, VIN, VOUT and the SW patch. |-| 1:55 | Current and heat | Adom Fields 0.5.0 on the first board, captured frame by frame: heat flow with the parts' own 3D models standing see-through on the board (U1 +51 °C, L1 +43 °C), then a slow fly-in to the 215 A/mm² SW neck at U1 pin 2. |-| 2:10 | The rework | First run's routing rework, then the rework run's second routing visit, then the SW neck in KiCad with a ring around it, and Adom Fields on the final board: U1 +44 °C, L1 +41 °C over their parts. |-| 2:27 | Silkscreen, placed live | Rework run, the 16-minute live silkscreen session at about 88x. |-| 2:38 | Part models | Native KiCad 10 renders of the board before and after the part-model cleanup, then a smooth close-up of D1 from its etched side. |-| 2:54 | On the Adom wiki | The live wiki pages of L1, C1, D1 and C2/C3, each scrolled from its 3D model down to its symbol and footprint (headless browser capture). |-| 3:08 | What it cost | A cost card: tokens and model calls for the board's build and rework runs, their price at Claude API rates, and the practical cost on a 20x plan. |-| 3:27 | Adom, all together | Filmed in Adom Hydrogen on a second PC: a Claude thread is asked which Adom tools built the board and answers from the wiki page, while the teal Adom AI cursor switches the webview between the board page (3D, Hero view) and the TPS54202 page (3D chip, symbol with its chip outline, footprint, the chip-outline widget), next to the EDA tools dock. |-| 3:48 | Logo sting | The dark Adom outro sting, under the last line of narration. |--The step recordings are the ones on the [build clips](clips.md) and [rework clips](clips-rework.md) pages, taken from their raw 4K masters.--## What it cost--Counted from this board's own Claude Code thread and its sub-agents, inside the two runs' clocks (the build, 2026-09-29 00:39 to 17:01 UTC, and the rework, 2026-09-30 01:08 to 11:33 UTC). Only the board is counted: the making of this video, other threads open at the same time, and side work that was not part of designing this board are left out.--| | tokens |-|---|---|-| model calls (Claude Opus 5.5) | 1,312 |-| output | 839,190 |-| input (fresh) | 3,123 |-| cache reads | 556,832,341 |-| cache writes | 4,936,353 |--At Claude API pricing for Opus 5.5 ($4 input, $20 output, $0.20 cache read and $8 one-hour cache write per million tokens) that is about **$168**. On a 20x subscription plan, divide by 20: about **$8**.--## The voice-over script--Spoken by adom-tts (the Andrew voice). Part numbers and units are written out the way they are spoken; the subtitles show the written form.--**The prompt.** It starts with one prompt, typed into Claude Code in Adom Hydrogen: create a twelve volt to five volt, one amp buck converter, using TI's T P S five four two oh two, as an Adom molecule.--**Opening.** From that one prompt, Claude did the rest: the circuit math, three simulators, the layout in KiCad, the analysis, the part models and the documentation, all with Adom's tools. Here's how it went.--**The circuit.** Claude worked the circuit out from the datasheet. The regulator's symbol carries its own chip outline, and the big capacitor, the inductor and the L E D show theirs beside their symbols: Adom Symbol and Adom L B R turned each part's STEP model into that drawing, on Adom's Open Cascade service. And every value comes from the equations: a fifteen microhenry inductor, three twenty-two microfarad output capacitors, and a sixty-eight picofarad feed-forward capacitor that shapes the loop.--**Simulation.** Before any copper, the design was simulated in three engines at once, on the Adom SPICE dashboard, right in Hydrogen's webview, beside the AI that runs it. N G spice runs in the container. L T spice, and TI's P spice, run on a Windows PC, their windows driven by the AI through Adom Bridge. Start-up, both load steps, and the inductor ripple all overlay: three engines, eight measurements, all in agreement.--**Placement.** Then the board. Adom AI Flow drives KiCad ten through the Adom KiCad Bridge, live. Twenty-four parts move onto a twenty-eight by twenty millimetre molecule, with the hot loop packed tight around the regulator.--**Routing and pours.** The routing lands as forty-eight traces, each one checked against KiCad's own design rules before it commits. Then the copper pours flood in: a solid ground, wide input and output planes, and a patch for the switch node.--**Current and heat.** Then the physics. Adom Fields solves current density and heat on the real copper. It found a choke point: two hundred fifteen amps per square millimetre in the neck of the switch node, right at the regulator. So the flow sent the board back.--**The rework.** Back to routing, and back to the pours. The sense trace moved off the ground plane, the switch patch got wider, and thermal vias went in under the regulator. The neck dropped to fifty amps per square millimetre, and the regulator now runs forty-four degrees over ambient, in still air.--**Silkscreen, placed live.** Next, the silkscreen, placed live, group by group: ninety-seven labels, each part's name large and its value small, with nothing sitting on a pad.--**Part models.** Then every 3D model got the same attention. Each part number is laser-etched flat onto the part, in the part's own colours. The LED is tinted to its datasheet wavelength, with its marking on the side, so the window stays clear. And every height matches its datasheet.--**On the Adom wiki.** Every part on this board now has its own page on the Adom wiki, for every Adom user: the inductor, the capacitors, the resistors and the LED, each with its 3D model, symbol and footprint.--**What it cost.** What did it cost? Building the board took about eight hundred forty thousand output tokens, and five hundred sixty million tokens read back from the prompt cache. At Claude A P I pricing, that's about a hundred sixty-eight dollars. On a twenty X plan, divide by twenty: about eight dollars.--**Adom, all together.** That's the real story: Adom's tools working together, inside Hydrogen. Claude drove KiCad and three simulators through Adom Bridge. Adom Parts Search found the parts, Adom AI Flow ran the flow, and Adom Fields checked the copper. Adom Chip Laser etched every part number, Adom Symbol and Adom L B R drew the symbols on our Open Cascade service, and the Adom wiki holds it all. One prompt, and a better board.--## Review and tools--Every scene was loaded into adom-video-post's storyboard as its own clip and reviewed one by one before assembly. Narration is synthesised per scene with adom-tts; frames are composited by a small Python renderer with the brand fonts from the gang-takes helpers in [adom/adom-video-post](https://wiki.adom.inc/adom/adom-video-post); ffmpeg cross-dissolves the scenes and normalises loudness (-16 LUFS). The [aiflow-process-video](https://wiki.adom.inc/adom/adom-aiflow) skill in adom-aiflow now carries these practices for the next board.