// PDN study of the 3.3 V rail: one buck output + a backup LDO feeding
// three loads. Loads sink fixed currents; supplies are Thevenin
// sources (v_oc behind r_out_ohm; v_oc defaults to run.v_nominal).
// "rect:CAM_ZONE" names a rectangle drawn on User.3 with a text item
// "CAM_ZONE" placed inside it. Part references: "U7" = all pads of U7
// on the run net, "U1.SW2" = one pad, {"rect_mm": ...} = explicit
// area, {"via_mm": ...} = nearest via.
{
    "version": 1,
    "mode": "pdn",
    "run": {
        "net": "VCC_3V3",
        "v_nominal": 3.30,
        "freq_hz": 0,
        "adaptive": true
    },
    "terminals": [
        {"name": "buck", "role": "supply",
         "parts": ["U1.SW2", "U1.SW3"],
         "r_out_ohm": 0.004},
        {"name": "ldo_backup", "role": "supply",
         "parts": ["U2.OUT"],
         "r_out_ohm": 0.050, "v_oc": 3.28},
        // bonded: all of U7's pins are one internally-joined lug -
        // the 1.8 A total is prescribed, the per-pin split is a solve
        // outcome (default false = per-cell area share instead)
        {"name": "mcu_core", "role": "load",
         "parts": ["U7"],
         "i_draw_a": 1.8, "bonded": true,
         "comment": "worst-case core draw, DS table 5-2"},
        {"name": "camera_module", "role": "load",
         "parts": ["rect:CAM_ZONE"],
         "i_draw_a": 0.35, "contact": "F.Cu"},
        {"name": "heater", "role": "load",
         "parts": [{"rect_mm": [112.0, 40.5, 118.0, 44.0],
                    "contact": "B.Cu"},
                   {"via_mm": [115.2, 42.1]}],
         "i_draw_a": 2.5}
    ],
    "markers": {"pdn_layer": "User.3"}
}