feat: add explicit two-pad package identities

README.md

@@ -29,6 +29,8 @@ sot23
 qfn24_w6_h6_p0.8mm_thermalpad_startingpin(topside,rightpin)_ccw
 qfn64_thermalpad6.3mmx6.3mm_thermalvias4x4_thermalviapitch1mm_thermalviaid0.3048mm_thermalviaod0.6096mm
 axial_p0.2in
+do219ad
+sod323he
 ```
 
 You can use these like so:
@@ -113,6 +115,25 @@ fp().sod123w().p("3.4mm").pw("0.95mm").cathodepin(1)
 fp().sod123w().p("3.4mm").pw("0.95mm").anodepin(1)
 ```
 
+### Explicit two-pad package identity
+
+Two rectangular pads alone do not identify the component package. Use a named
+standard-family footprint when downstream tools such as a 3D renderer need an
+unambiguous package identity:
+
+```ts
+fp.string("do219ad")
+fp.string("sod323he")
+fp.string("dfn2_w1.6mm_pl0.6mm_pw0.6mm")
+```
+
+`do-219ad` and `sod-323he` are accepted aliases and normalize to the canonical
+names above. DO-219AD and SOD-323HE assign pin 1 to the cathode at negative X
+and pin 2 to the anode at positive X. Their land-pattern parameters (`p`, `pw`,
+and `ph`) are independent from their validated mechanical parameters such as
+`bodylength`, `bodywidth`, and `bodyheight`. A generic `smdpads2` footprint
+remains generic and never selects one of these packages by pad dimensions.
+
 ### Rounded pads
 
 Every footprint accepts a `rounded${radius}` modifier that applies the requested

src/fn/dfn.ts

@@ -4,18 +4,42 @@ import type {
   PcbSilkscreenPath,
 } from "circuit-json"
 import { length } from "circuit-json"
-import { extendSoicDef, getCcwSoicCoords } from "./soic"
-import { rectpad } from "src/helpers/rectpad"
-import { pillpad } from "src/helpers/pillpad"
-import { z } from "zod"
 import { CORNERS } from "src/helpers/corner"
-import { type SilkscreenRef, silkscreenRef } from "src/helpers/silkscreenRef"
-import { function_call } from "src/helpers/zod/function-call"
 import { createThermalPad } from "src/helpers/create-thermal-pad"
 import { addThermalVias, thermalViaDef } from "src/helpers/create-thermal-vias"
+import { pillpad } from "src/helpers/pillpad"
 import { polygonpad } from "src/helpers/polygonpad"
+import { rectpad } from "src/helpers/rectpad"
+import { type SilkscreenRef, silkscreenRef } from "src/helpers/silkscreenRef"
+import { function_call } from "src/helpers/zod/function-call"
+import { z } from "zod"
+import { extendSoicDef, getCcwSoicCoords } from "./soic"
 
-export const dfn_def = extendSoicDef({}).and(thermalViaDef)
+const positiveMechanicalLength = length.refine((value) => value > 0, {
+  message: "DFN mechanical dimension must be positive",
+})
+const nonnegativeMechanicalLength = length.refine((value) => value >= 0, {
+  message: "DFN mechanical dimension must be non-negative",
+})
+
+/** Optional physical-package dimensions for an explicitly named DFN model. */
+export const dfn_mechanical_def = z.object({
+  bodywidth: positiveMechanicalLength.optional(),
+  bodylength: positiveMechanicalLength.optional(),
+  bodythickness: positiveMechanicalLength.optional(),
+  standoff: nonnegativeMechanicalLength.optional(),
+  terminalinset: nonnegativeMechanicalLength.optional(),
+  terminallength: positiveMechanicalLength.optional(),
+  terminalwidth: positiveMechanicalLength.optional(),
+  terminalpitch: positiveMechanicalLength.optional(),
+  terminalthickness: positiveMechanicalLength.optional(),
+  pin1terminalchamfer: nonnegativeMechanicalLength.optional(),
+  pin1markwidth: nonnegativeMechanicalLength.optional(),
+})
+
+export const dfn_def = extendSoicDef({})
+  .and(thermalViaDef)
+  .and(dfn_mechanical_def)
 export type DfnInput = z.input<typeof dfn_def> & {
   /** Replace the four rectangular DFN pads with chamfered corner pads. */
   cornerpads?: boolean
@@ -53,6 +77,27 @@ export const dfn = (
     cornerpadcutlength,
     missing: missingPositions,
   }
+  if (
+    parameters.bodythickness !== undefined &&
+    parameters.standoff !== undefined &&
+    parameters.standoff >= parameters.bodythickness
+  ) {
+    throw new Error("DFN standoff must be less than bodythickness")
+  }
+  if (
+    parameters.terminalthickness !== undefined &&
+    parameters.bodythickness !== undefined &&
+    parameters.terminalthickness > parameters.bodythickness
+  ) {
+    throw new Error("DFN terminalthickness must not exceed bodythickness")
+  }
+  if (
+    parameters.pin1markwidth !== undefined &&
+    parameters.bodywidth !== undefined &&
+    parameters.pin1markwidth >= parameters.bodywidth / 2
+  ) {
+    throw new Error("DFN pin1markwidth must be less than half bodywidth")
+  }
   const nominalPinCount = parameters.num_pins
   if (
     missingPositions.some(

src/fn/do219ad.ts

@@ -0,0 +1,41 @@
+import type { AnyCircuitElement } from "circuit-json"
+import type { z } from "zod"
+import {
+  createStandardFlatLeadDiodeCircuitJson,
+  createStandardFlatLeadDiodeDef,
+} from "../helpers/standard-flat-lead-diode"
+
+/**
+ * JEDEC DO-219AD (MicroSMP), using nominal Vishay package dimensions.
+ * Dimensional reference: https://www.vishay.com/doc/?89019=
+ */
+export const do219ad_def = createStandardFlatLeadDiodeDef("do219ad", {
+  p: "1.84mm",
+  pw: "1.35mm",
+  ph: "0.95mm",
+  bodylength: "2.2mm",
+  bodywidth: "1.3mm",
+  bodyheight: "0.68mm",
+  leadspan: "2.5mm",
+  cathodelength: "1.3mm",
+  cathodewidth: "0.88mm",
+  anodelength: "0.65mm",
+  anodewidth: "0.65mm",
+  terminalthickness: "0.195mm",
+  standoff: "0.11mm",
+  taperinset: "0.05mm",
+  markingwidth: "0.23mm",
+})
+
+export const do219ad = (
+  rawParameters: z.input<typeof do219ad_def>,
+): {
+  circuitJson: AnyCircuitElement[]
+  parameters: z.output<typeof do219ad_def>
+} => {
+  const parameters = do219ad_def.parse(rawParameters)
+  return {
+    circuitJson: createStandardFlatLeadDiodeCircuitJson(parameters),
+    parameters,
+  }
+}

src/fn/index.ts

@@ -22,6 +22,7 @@ export { sot886 } from "./sot886"
 export { sot23 } from "./sot23"
 export { sot25 } from "./sot25"
 export { dfn } from "./dfn"
+export { do219ad } from "./do219ad"
 export { pinrow } from "./pinrow"
 export { headermodule } from "./headermodule"
 export { sot563 } from "./sot563"
@@ -46,6 +47,7 @@ export { sop8 } from "./sop8"
 export { sod80 } from "./sod80"
 export { sod123w } from "./sod123w"
 export { sod323 } from "./sod323"
+export { sod323he } from "./sod323he"
 export { sod923 } from "./sod923"
 export { sod882 } from "./sod882"
 export { sod323f } from "./sod323f"

src/fn/sod323he.ts

@@ -0,0 +1,41 @@
+import type { AnyCircuitElement } from "circuit-json"
+import type { z } from "zod"
+import {
+  createStandardFlatLeadDiodeCircuitJson,
+  createStandardFlatLeadDiodeDef,
+} from "../helpers/standard-flat-lead-diode"
+
+/**
+ * JEITA SOD-323HE, using nominal ROHM package dimensions.
+ * Dimensional reference: https://www.rohm.com/products/diodes/fast-recovery-diodes/standard/rfu02vsm6s-product
+ */
+export const sod323he_def = createStandardFlatLeadDiodeDef("sod323he", {
+  p: "2.1001mm",
+  pw: "0.8mm",
+  ph: "1.1mm",
+  bodylength: "2mm",
+  bodywidth: "1.4mm",
+  bodyheight: "0.6mm",
+  leadspan: "2.5mm",
+  cathodelength: "0.55mm",
+  cathodewidth: "0.8mm",
+  anodelength: "0.55mm",
+  anodewidth: "0.8mm",
+  terminalthickness: "0.17mm",
+  standoff: "0.05mm",
+  taperinset: "0.15mm",
+  markingwidth: "0.2mm",
+})
+
+export const sod323he = (
+  rawParameters: z.input<typeof sod323he_def>,
+): {
+  circuitJson: AnyCircuitElement[]
+  parameters: z.output<typeof sod323he_def>
+} => {
+  const parameters = sod323he_def.parse(rawParameters)
+  return {
+    circuitJson: createStandardFlatLeadDiodeCircuitJson(parameters),
+    parameters,
+  }
+}

src/footprinter.ts

@@ -214,6 +214,36 @@ export type Footprinter = {
     | "thermalviaod"
     | "cornerpads"
     | "cornerpadcutlength"
+    | "bodywidth"
+    | "bodylength"
+    | "bodythickness"
+    | "standoff"
+    | "terminalinset"
+    | "terminallength"
+    | "terminalwidth"
+    | "terminalpitch"
+    | "terminalthickness"
+    | "pin1terminalchamfer"
+    | "pin1markwidth"
+  >
+  do219ad: () => FootprinterParamsBuilder<
+    | "p"
+    | "pw"
+    | "ph"
+    | "cyw"
+    | "cyh"
+    | "bodylength"
+    | "bodywidth"
+    | "bodyheight"
+    | "leadspan"
+    | "cathodelength"
+    | "cathodewidth"
+    | "anodelength"
+    | "anodewidth"
+    | "terminalthickness"
+    | "standoff"
+    | "taperinset"
+    | "markingwidth"
   >
   pinrow: (
     num_pins?: number,
@@ -376,6 +406,25 @@ export type Footprinter = {
   electrolytic: () => FootprinterParamsBuilder<"d" | "p" | "id" | "od">
   sod923: () => FootprinterParamsBuilder<"w" | "h" | "p" | "pl" | "pw">
   sod323: () => FootprinterParamsBuilder<"w" | "h" | "p" | "pl" | "pw">
+  sod323he: () => FootprinterParamsBuilder<
+    | "p"
+    | "pw"
+    | "ph"
+    | "cyw"
+    | "cyh"
+    | "bodylength"
+    | "bodywidth"
+    | "bodyheight"
+    | "leadspan"
+    | "cathodelength"
+    | "cathodewidth"
+    | "anodelength"
+    | "anodewidth"
+    | "terminalthickness"
+    | "standoff"
+    | "taperinset"
+    | "markingwidth"
+  >
   sod80: () => FootprinterParamsBuilder<"w" | "h" | "p" | "pl" | "pw">
   sod882: () => FootprinterParamsBuilder<"w" | "h" | "p" | "pl" | "pw">
   sod882d: () => FootprinterParamsBuilder<"w" | "h" | "p" | "pl" | "pw">
@@ -584,6 +633,8 @@ export type Footprinter = {
 const normalizeDefinition = (def: string): string => {
   return def
     .trim()
+    .replace(/^do-219ad(?=_|$)/i, "do219ad")
+    .replace(/^sod-323he(?=_|$)/i, "sod323he")
     .replace(/^pinheader(?=[\d_]|$)/i, "pinrow")
     .replace(/^d2pak(\d+)(?=_|$)/i, "d2pak_$1")
     .replace(/^to-252(?:-(\d+))?(?=_|$)/i, (_, pins) =>
@@ -632,7 +683,7 @@ export const string = (def: string): Footprinter => {
       // parameter name. Require another value token after that name so a
       // normal pitch such as p1mm is still parsed as p + 1mm.
       const m = s.match(
-        /((?:p\d+[a-zA-Z]+(?=[\(\d\.\+\-\?]))|[a-zA-Z]+)([\(\d\.\+\-\?].*)?/,
+        /((?:(?:p\d+|pin1)[a-zA-Z]+(?=[\(\d\.\+\-\?]))|[a-zA-Z]+)([\(\d\.\+\-\?].*)?/,
       )
       if (!m) return null
       const [, rawFn, v] = m