Add schematic filter topology and LDO/resistor thermal checks.

Match RC/LC/π/T without inventing fc, compare to ADC rate only when specs list it, and skip ferrite DCR unless the IC gives a limit. LDO Tj uses I_load not Iout_max, and missing θJA stays INFO. Co-authored-by: Cursor <cursoragent@cursor.com>
2026-09-10 22:28:40 +02:00
parent 4403c38d96
commit a45a06e761
8 changed files with 1070 additions and 4 deletions
@@ -0,0 +1,144 @@
+"""LDO/resistor thermal — no invented I_load or θJA."""
+
+from __future__ import annotations
+
+from backend.pinscopex.models import (
+    Component,
+    ComponentConstraints,
+    ComponentType,
+    DesignGraph,
+    Net,
+    NetType,
+    Pin,
+    PinConnection,
+    ResistorSpecs,
+    SimpleComponentSpecs,
+)
+from backend.pinscopex.thermal_check import check_thermal
+
+
+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 _ldo(values, subtype="ic.power.ldo"):
+    return Component(
+        reference="U1", value="", footprint="",
+        component_type=ComponentType.IC, component_subtype=subtype,
+        mpn="LDOX",
+        pins={"1": "VIN", "2": "VOUT", "3": "GND"},
+        specs=SimpleComponentSpecs(specs_type="ic", component_subtype=subtype, values=values),
+    )
+
+
+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 test_ldo_without_theta_ja_is_info():
+    g = _graph(
+        {"U1": _ldo({"i_load_a": 0.2})},
+        {
+            "VIN": (NetType.POWER, 5.0, [("U1", "1")]),
+            "VOUT": (NetType.POWER, 3.3, [("U1", "2")]),
+            "GND": (NetType.GROUND, 0.0, [("U1", "3")]),
+        },
+    )
+    findings = check_thermal(g, _cons())
+    assert len(findings) == 1
+    assert findings[0].rule_id == "PS-TH-001"
+    assert findings[0].status == "INFO"
+    assert "theta_ja" in findings[0].finding.lower() or "theta_ja" in findings[0].why.lower()
+
+
+def test_iout_max_is_not_used_as_load():
+    g = _graph(
+        {"U1": _ldo({"iout_max_a": 0.5, "theta_ja": 160})},
+        {
+            "VIN": (NetType.POWER, 5.0, [("U1", "1")]),
+            "VOUT": (NetType.POWER, 3.3, [("U1", "2")]),
+            "GND": (NetType.GROUND, 0.0, [("U1", "3")]),
+        },
+    )
+    assert check_thermal(g, _cons()) == []
+
+
+def test_ldo_hot_tj_is_warning():
+    # 0.5 A * 1.7 V = 0.85 W * 160 °C/W + 25 = 161 °C
+    g = _graph(
+        {"U1": _ldo({"i_load_a": 0.5, "theta_ja": 160})},
+        {
+            "VIN": (NetType.POWER, 5.0, [("U1", "1")]),
+            "VOUT": (NetType.POWER, 3.3, [("U1", "2")]),
+            "GND": (NetType.GROUND, 0.0, [("U1", "3")]),
+        },
+    )
+    findings = check_thermal(g, _cons())
+    assert len(findings) == 1
+    assert findings[0].rule_id == "PS-TH-002"
+    assert findings[0].status == "WARNING"
+
+
+def test_shunt_over_rating_is_warning():
+    r = Component(
+        reference="R1", value="1", footprint="",
+        component_type=ComponentType.RESISTOR, mpn="R1",
+        pins={"1": "A", "2": "B"},
+        specs=ResistorSpecs(value_ohms=1.0, value_formatted="1", power_rating_w="0.125"),
+    )
+    g = _graph(
+        {"R1": r},
+        {
+            "A": (NetType.POWER, 3.3, [("R1", "1")]),
+            "B": (NetType.POWER, 0.0, [("R1", "2")]),
+        },
+    )
+    findings = check_thermal(g)
+    assert len(findings) == 1
+    assert findings[0].rule_id == "PS-TH-003"
+    assert findings[0].status == "WARNING"
+
+
+def test_led_resistor_within_rating_is_silent():
+    led = Component(
+        reference="D1", value="LED", footprint="",
+        component_type=ComponentType.DISCRETE, component_subtype="discrete.led",
+        mpn="LEDX",
+        pins={"A": "+5V", "K": "NetK"},
+        specs=SimpleComponentSpecs(
+            specs_type="discrete", component_subtype="discrete.led",
+            values={"forward_voltage_v": 2.0, "forward_current_a": "20mA"},
+        ),
+    )
+    r = Component(
+        reference="R1", value="330", footprint="",
+        component_type=ComponentType.RESISTOR, mpn="R1",
+        pins={"1": "NetK", "2": "GND"},
+        specs=ResistorSpecs(value_ohms=330.0, value_formatted="330", power_rating_w="0.125"),
+    )
+    g = _graph(
+        {"D1": led, "R1": r},
+        {
+            "+5V": (NetType.POWER, 5.0, [("D1", "A")]),
+            "NetK": (NetType.SIGNAL, None, [("D1", "K"), ("R1", "1")]),
+            "GND": (NetType.GROUND, 0.0, [("R1", "2")]),
+        },
+    )
+    assert check_thermal(g) == []