Show cached passives in the library and match IC PDFs by family MPN.

Decode EIA/Yageo/AVX chip codes into library specs, and find datasheets when the file is stored under the orderable catalog name. Co-authored-by: Cursor <cursoragent@cursor.com>
2026-08-28 02:27:27 +02:00
parent 3be7d2fc21
commit 08cbbdc422
11 changed files with 534 additions and 80 deletions
@@ -0,0 +1,139 @@
+"""Decode common chip R/C MPNs into typed specs without an LLM.
+
+Only encodings that carry package + value (and voltage for capacitors when
+the manufacturer puts it in the code) are accepted. Incomplete BOM-value
+guesses stay out of the shared library.
+"""
+
+from __future__ import annotations
+
+import re
+
+from backend.pinscopex.models import ComponentModel, SimpleComponentSpecs
+from backend.pinscopex.resolve_passives import simple_to_typed_passive_specs
+from backend.services.passive_from_distributor import _spice
+
+_SIZE = r"(?:0201|0402|0603|0805|1206|1210|1812|2010|2512)"
+_DIEL = r"(?:C0G|NP0|CG|X8R|X7R|X7S|X6S|X5R|Y5V)"
+_TOL = {
+    "B": "±0.1%",
+    "C": "±0.25%",
+    "D": "±0.5%",
+    "F": "±1%",
+    "G": "±2%",
+    "J": "±5%",
+    "K": "±10%",
+    "M": "±20%",
+}
+_AVX_V = {
+    "4": "4V",
+    "6": "6.3V",
+    "Z": "10V",
+    "Y": "16V",
+    "3": "25V",
+    "5": "50V",
+    "1": "100V",
+    "2": "200V",
+    "7": "500V",
+}
+_AVX_DIEL = {"A": "C0G", "C": "X7R", "D": "X5R", "Z": "Y5V"}
+_DIEL_NORM = {"CG": "C0G", "NP0": "C0G"}
+
+_WALSIN_CAP = re.compile(
+    rf"^({_SIZE})({_DIEL})(\d{{3}})([{''.join(_TOL)}])(\d{{3}}|[0-9]R[0-9])",
+    re.IGNORECASE,
+)
+_AVX_CAP = re.compile(
+    rf"^({_SIZE})([46ZY35127])([{''.join(_AVX_DIEL)}])(\d{{3}})([{''.join(_TOL)}])",
+    re.IGNORECASE,
+)
+_CHIP_R = re.compile(
+    rf"^(?:FRC)?({_SIZE})(?:W\d)?([{''.join('FJKG')}])(\d{{4}})",
+    re.IGNORECASE,
+)
+
+
+def _eia3_pf(digits: str) -> float:
+    return float(int(digits[:2]) * (10 ** int(digits[2])))
+
+
+def _eia3_volts(code: str) -> str | None:
+    code = code.upper()
+    if "R" in code:
+        try:
+            return f"{float(code.replace('R', '.')):g}V"
+        except ValueError:
+            return None
+    if len(code) != 3 or not code.isdigit():
+        return None
+    volts = int(code[:2]) * (10 ** int(code[2]))
+    return f"{volts}V"
+
+
+def _eia4_ohm(digits: str) -> float:
+    return float(int(digits[:3]) * (10 ** int(digits[3])))
+
+
+def _model(mpn: str, subtype: str, values: dict[str, str]) -> ComponentModel | None:
+    specs = SimpleComponentSpecs(
+        specs_type="passive",
+        component_subtype=subtype,
+        values=values,
+    )
+    try:
+        typed = simple_to_typed_passive_specs(specs)
+    except (ValueError, TypeError):
+        return None
+    return ComponentModel(mpn=mpn, specs=typed)
+
+
+def specs_from_mpn(mpn: str) -> ComponentModel | None:
+    """Return a ComponentModel when the MPN itself encodes enough specs."""
+    raw = (mpn or "").strip()
+    if not raw:
+        return None
+
+    m = _WALSIN_CAP.match(raw)
+    if m:
+        size, diel, cap, tol, volt = m.groups()
+        pf = _eia3_pf(cap)
+        values = {
+            "value_farads": _spice(str(pf), "p", "F") if pf else None,
+            "package": size.upper(),
+            "dielectric": _DIEL_NORM.get(diel.upper(), diel.upper()),
+            "tolerance": _TOL[tol.upper()],
+        }
+        rated = _eia3_volts(volt)
+        if rated:
+            values["voltage_rating_v"] = rated
+        values["value_formatted"] = values["value_farads"]
+        if values["value_farads"]:
+            return _model(raw, "passive.capacitor.ceramic", values)
+
+    m = _AVX_CAP.match(raw)
+    if m:
+        size, vcode, diel, cap, tol = m.groups()
+        pf = _eia3_pf(cap)
+        values = {
+            "value_farads": _spice(str(pf), "p", "F"),
+            "value_formatted": _spice(str(pf), "p", "F"),
+            "package": size.upper(),
+            "dielectric": _AVX_DIEL[diel.upper()],
+            "tolerance": _TOL[tol.upper()],
+            "voltage_rating_v": _AVX_V[vcode.upper()],
+        }
+        return _model(raw, "passive.capacitor.ceramic", values)
+
+    m = _CHIP_R.match(raw)
+    if m:
+        size, tol, code = m.groups()
+        ohms = _eia4_ohm(code)
+        values = {
+            "value_ohms": _spice(str(ohms), None, "ohm"),
+            "value_formatted": _spice(str(ohms), None, "ohm"),
+            "package": size.upper(),
+            "tolerance": _TOL[tol.upper()],
+        }
+        return _model(raw, "passive.resistor.thick_film", values)
+
+    return None