Add power-margin, PG-to-EN sequencing, and DNP enable checks.

Compare only specified IQ plus I_load to Iout_max and series-R drop, flag sequencing only when power_sequence is in specs, and treat DNP as a fitted-variant graph so a missing enable pull is ERROR only when the BOM actually marks DNP. Co-authored-by: Cursor <cursoragent@cursor.com>
2026-09-10 22:34:06 +02:00
parent a45a06e761
commit 78013bd404
13 changed files with 800 additions and 8 deletions
@@ -0,0 +1,124 @@
+"""Regulator Iout margin and series-R IR drop — no invented IQ or traces."""
+
+from __future__ import annotations
+
+from backend.pinscopex.models import (
+    Component,
+    ComponentConstraints,
+    ComponentType,
+    DesignGraph,
+    Net,
+    NetType,
+    Pin,
+    PinConnection,
+    ResistorSpecs,
+    SimpleComponentSpecs,
+)
+from backend.pinscopex.power_margin_check import check_power_margin
+
+
+def _graph(components, nets):
+    net_objs = {}
+    for name, (ntype, volt, conns) in nets.items():
+        net_objs[name] = Net(
+            name=name, net_type=ntype, voltage=volt,
+            pins=[PinConnection(component_ref=r, pin_number=str(p)) for r, p in conns],
+        )
+    return DesignGraph(components=components, nets=net_objs)
+
+
+def _cons():
+    return {
+        "LDOX": ComponentConstraints(
+            mpn="LDOX", component_subtype="ic.power.ldo",
+            pintable=[
+                Pin(number=1, name="VIN"),
+                Pin(number=2, name="VOUT"),
+                Pin(number=3, name="GND"),
+            ],
+            absolute_maximum_ratings=[], rules=[],
+        )
+    }
+
+
+def _ldo(values):
+    return Component(
+        reference="U1", value="", footprint="",
+        component_type=ComponentType.IC, component_subtype="ic.power.ldo",
+        mpn="LDOX",
+        pins={"1": "VIN", "2": "VOUT", "3": "GND"},
+        specs=SimpleComponentSpecs(specs_type="ic", component_subtype="ic.power.ldo", values=values),
+    )
+
+
+def _mcu(iq=None):
+    values = {} if iq is None else {"iq_a": iq}
+    return Component(
+        reference="U2", value="", footprint="",
+        component_type=ComponentType.IC, mpn="MCU",
+        pins={"1": "VOUT", "2": "GND"},
+        specs=SimpleComponentSpecs(specs_type="ic", values=values) if values else None,
+    )
+
+
+def test_load_over_iout_max_is_ps_pwr_001():
+    g = _graph(
+        {
+            "U1": _ldo({"i_load_a": 0.4, "iout_max_a": 0.5}),
+            "U2": _mcu(0.2),
+        },
+        {
+            "VIN": (NetType.POWER, 5.0, [("U1", "1")]),
+            "VOUT": (NetType.POWER, 3.3, [("U1", "2"), ("U2", "1")]),
+            "GND": (NetType.GROUND, 0.0, [("U1", "3"), ("U2", "2")]),
+        },
+    )
+    findings = check_power_margin(g, _cons())
+    assert any(f.rule_id == "PS-PWR-001" and f.designator == "U1" for f in findings)
+
+
+def test_missing_iq_is_not_guessed_into_margin_fail():
+    g = _graph(
+        {
+            "U1": _ldo({"iout_max_a": 0.1}),
+            "U2": _mcu(None),
+        },
+        {
+            "VIN": (NetType.POWER, 5.0, [("U1", "1")]),
+            "VOUT": (NetType.POWER, 3.3, [("U1", "2"), ("U2", "1")]),
+            "GND": (NetType.GROUND, 0.0, [("U1", "3"), ("U2", "2")]),
+        },
+    )
+    assert check_power_margin(g, _cons()) == []
+
+
+def test_series_r_ir_drop_uses_i_load_not_trace():
+    r = Component(
+        reference="R1", value="1", footprint="",
+        component_type=ComponentType.RESISTOR, mpn="R1",
+        pins={"1": "USB", "2": "VIN"},
+        specs=ResistorSpecs(value_ohms=1.0, value_formatted="1"),
+    )
+    g = _graph(
+        {"U1": _ldo({"i_load_a": 0.5, "iout_max_a": 1.0}), "R1": r},
+        {
+            "USB": (NetType.POWER, 5.0, [("R1", "1")]),
+            "VIN": (NetType.POWER, 5.0, [("R1", "2"), ("U1", "1")]),
+            "VOUT": (NetType.POWER, 3.3, [("U1", "2")]),
+            "GND": (NetType.GROUND, 0.0, [("U1", "3")]),
+        },
+    )
+    findings = check_power_margin(g, _cons())
+    assert any(f.designator == "R1" and f.rule_id == "PS-PWR-001" for f in findings)
+
+
+def test_no_series_r_does_not_invent_trace_drop():
+    g = _graph(
+        {"U1": _ldo({"i_load_a": 0.5, "iout_max_a": 1.0})},
+        {
+            "VIN": (NetType.POWER, 5.0, [("U1", "1")]),
+            "VOUT": (NetType.POWER, 3.3, [("U1", "2")]),
+            "GND": (NetType.GROUND, 0.0, [("U1", "3")]),
+        },
+    )
+    assert check_power_margin(g, _cons()) == []