Implement UTDFN-4-EP(1x1) footprint

src/fn/index.ts

@@ -81,3 +81,4 @@ export { sot343 } from "./sot343"
 export { m2host } from "./m2host"
 export { mountedpcbmodule } from "./mountedpcbmodule"
 export { to92l } from "./to92l"
+export { utdfn } from "./utdfn"

src/fn/utdfn.ts

@@ -0,0 +1,107 @@
+import type {
+  AnyCircuitElement,
+  PcbCourtyardRect,
+  PcbSilkscreenPath,
+} from "circuit-json"
+import { z } from "zod"
+import { rectpad } from "src/helpers/rectpad"
+import { base_def } from "../helpers/zod/base_def"
+import { type SilkscreenRef, silkscreenRef } from "src/helpers/silkscreenRef"
+
+export const utdfn_def = base_def.extend({
+  fn: z.string(),
+  num_pins: z.number().default(4),
+  w: z.string().default("0.90mm"),
+  p: z.string().default("0.65mm"),
+  pl: z.string().default("0.40mm"),
+  pw: z.string().default("0.25mm"),
+  epw: z.string().default("0.48mm"),
+  eph: z.string().default("0.48mm"),
+  string: z.string().optional(),
+})
+
+export const utdfn = (
+  raw_params: z.input<typeof utdfn_def>,
+): { circuitJson: AnyCircuitElement[]; parameters: any } => {
+  const parameters = utdfn_def.parse(raw_params)
+  const w = parseFloat(parameters.w)
+  const p = parseFloat(parameters.p)
+  const pl = parseFloat(parameters.pl)
+  const pw = parseFloat(parameters.pw)
+  const epw = parseFloat(parameters.epw)
+  const eph = parseFloat(parameters.eph)
+
+  const pads: AnyCircuitElement[] = []
+
+  // Generate the 4 pins in CCW order starting from bottom-left (Pin 1)
+  pads.push(rectpad(1, -w / 2, -p / 2, pl, pw))
+  pads.push(rectpad(2, -w / 2, p / 2, pl, pw))
+  pads.push(rectpad(3, w / 2, p / 2, pl, pw))
+  pads.push(rectpad(4, w / 2, -p / 2, pl, pw))
+
+  // Pin 5: Center Exposed Pad (EP)
+  pads.push(rectpad(5, 0, 0, epw, eph))
+
+  // Silkscreen: 2 horizontal lines
+  const sw = w + pl
+  const sh = p + pw + 0.3
+  const silkscreenPaths: PcbSilkscreenPath[] = []
+
+  silkscreenPaths.push({
+    layer: "top",
+    pcb_component_id: "",
+    pcb_silkscreen_path_id: "",
+    type: "pcb_silkscreen_path",
+    route: [
+      { x: -sw / 2 + 0.1, y: sh / 2 },
+      { x: sw / 2 - 0.1, y: sh / 2 },
+    ],
+    stroke_width: 0.08,
+  })
+  silkscreenPaths.push({
+    layer: "top",
+    pcb_component_id: "",
+    pcb_silkscreen_path_id: "",
+    type: "pcb_silkscreen_path",
+    route: [
+      { x: -sw / 2 + 0.1, y: -sh / 2 },
+      { x: sw / 2 - 0.1, y: -sh / 2 },
+    ],
+    stroke_width: 0.08,
+  })
+
+  // Pin 1 indicator line
+  silkscreenPaths.push({
+    layer: "top",
+    pcb_component_id: "",
+    pcb_silkscreen_path_id: "",
+    type: "pcb_silkscreen_path",
+    route: [
+      { x: -sw / 2 - 0.1, y: -sh / 2 },
+      { x: -sw / 2 - 0.2, y: -sh / 2 },
+    ],
+    stroke_width: 0.08,
+  })
+
+  const silkscreenRefText: SilkscreenRef = silkscreenRef(0, sh / 2 + 0.3, 0.2)
+
+  const courtyard: PcbCourtyardRect = {
+    type: "pcb_courtyard_rect",
+    pcb_courtyard_rect_id: "",
+    pcb_component_id: "",
+    center: { x: 0, y: 0 },
+    width: w + pl + 0.3,
+    height: p + pw + 0.5,
+    layer: "top",
+  }
+
+  return {
+    circuitJson: [
+      ...pads,
+      silkscreenRefText as AnyCircuitElement,
+      ...silkscreenPaths,
+      courtyard,
+    ],
+    parameters,
+  }
+}

src/footprinter.ts

@@ -40,6 +40,9 @@ export type Footprinter = {
   dip: (
     num_pins?: number,
   ) => FootprinterParamsBuilder<"w" | "p" | "id" | "od" | "wide" | "narrow">
+  utdfn: (
+    num_pins?: number,
+  ) => FootprinterParamsBuilder<"w" | "p" | "pl" | "pw" | "epw" | "eph">
   cap: () => FootprinterParamsBuilder<CommonPassiveOptionKey>
   res: () => FootprinterParamsBuilder<CommonPassiveOptionKey>
   diode: () => FootprinterParamsBuilder<CommonPassiveOptionKey>
@@ -275,6 +278,8 @@ const normalizeDefinition = (def: string): string => {
     .replace(/^sot-223-(\d+)(?=_|$)/i, "sot223_$1")
     .replace(/^to-220f-(\d+)(?=_|$)/i, "to220f_$1")
     .replace(/^jst_(ph|sh|zh)_(\d+)(?=_|$)/i, "jst$2_$1")
+    .replace(/^utdfn-4-ep\(1x1\)(?=_|$)/i, "utdfn4")
+    .replace(/^utdfn-4-ep(?=_|$)/i, "utdfn4")
 }
 
 export const string = (def: string): Footprinter => {

tests/utdfn.test.ts

@@ -0,0 +1,46 @@
+import { expect, test } from "bun:test"
+import { convertCircuitJsonToPcbSvg } from "circuit-to-svg"
+import { fp } from "../src/footprinter"
+
+test("utdfn-4-ep(1x1)", () => {
+  const circuitJson = fp.string("utdfn-4-ep(1x1)").circuitJson()
+
+  // Find all SMD pads
+  const pads = circuitJson.filter((e: any) => e.type === "pcb_smtpad")
+  expect(pads.length).toBe(5)
+
+  // Verify exposed pad (pad 5) is at center
+  const ep = pads.find((p: any) => p.port_hints?.includes("5"))
+  expect(ep).toBeDefined()
+  expect(ep.x).toBe(0)
+  expect(ep.y).toBe(0)
+  expect(ep.width).toBeCloseTo(0.48, 3)
+  expect(ep.height).toBeCloseTo(0.48, 3)
+
+  // Verify contact pad 1 (bottom-left)
+  const pad1 = pads.find((p: any) => p.port_hints?.includes("1"))
+  expect(pad1).toBeDefined()
+  expect(pad1.x).toBeCloseTo(-0.45, 3)
+  expect(pad1.y).toBeCloseTo(-0.325, 3)
+
+  // Verify contact pad 2 (top-left)
+  const pad2 = pads.find((p: any) => p.port_hints?.includes("2"))
+  expect(pad2).toBeDefined()
+  expect(pad2.x).toBeCloseTo(-0.45, 3)
+  expect(pad2.y).toBeCloseTo(0.325, 3)
+
+  // Verify contact pad 3 (top-right)
+  const pad3 = pads.find((p: any) => p.port_hints?.includes("3"))
+  expect(pad3).toBeDefined()
+  expect(pad3.x).toBeCloseTo(0.45, 3)
+  expect(pad3.y).toBeCloseTo(0.325, 3)
+
+  // Verify contact pad 4 (bottom-right)
+  const pad4 = pads.find((p: any) => p.port_hints?.includes("4"))
+  expect(pad4).toBeDefined()
+  expect(pad4.x).toBeCloseTo(0.45, 3)
+  expect(pad4.y).toBeCloseTo(-0.325, 3)
+
+  const svgContent = convertCircuitJsonToPcbSvg(circuitJson)
+  expect(svgContent).toMatchSvgSnapshot(import.meta.path, "utdfn-4-ep-1x1")
+})