From 228ff03cb641b1f6f0fc0d061b1a8b917e3cb0ef Mon Sep 17 00:00:00 2001 From: Dennis Brentjes Date: Fri, 2 Oct 2026 08:52:34 +0000 Subject: [PATCH] schematic: eFuse OVLO ladder + ILIM fix (V2.1) Implements the values worked out in 6ce7657. R45 100k -> 33k ILIM 0.52 A -> 1.52 A (clears the 621 mA inrush) R46 620k -> 150k ladder R1: 12V_RAW -> EN/UVLO R47 100k -> 10k ladder R2: EN/UVLO -> OVLO R48 NEW 12k \ ladder R3 = 14.2k: OVLO -> GND R49 NEW 2.2k / U13 pin 2 (OVLO) taken off GND and onto the new EFUSE_OVLO net Verified: netlist shows 12V_RAW(R46.1) / EFUSE_EN(R46.2,R47.1,U13.5) / EFUSE_OVLO(R47.2,R48.1,U13.2) / EFUSE_R3MID(R48.2,R49.1) / GND(R49.2,R45.2, U13.4); 150 -> 152 components with none dropped (the malformed-property trap from the kicad-bom-edit skill); ERC 0 violations. PCB placement and routing still to do. Co-Authored-By: Claude Opus 5 --- hardware/re-bba-rb/TODO.md | 12 +- hardware/re-bba-rb/exi.kicad_sch | 551 ++++++++++++++++++++++--------- 2 files changed, 396 insertions(+), 167 deletions(-) diff --git a/hardware/re-bba-rb/TODO.md b/hardware/re-bba-rb/TODO.md index f7f6743..9cf4eb3 100644 --- a/hardware/re-bba-rb/TODO.md +++ b/hardware/re-bba-rb/TODO.md @@ -246,15 +246,21 @@ schematic changes. the TPS25961 selects the internal *fixed* overvoltage cutoff ~5.98 V — so a 12 V rail is permanently in overvoltage lockout and the eFuse passes nothing (bench-confirmed: 12V_EXI=0, GC_ON=0, W5100 unpowered). - **FIX WORKED OUT FROM THE DATASHEET 2026-10-02 — values final, needs - schematic + PCB work.** TI 3-resistor ladder (§8.2.3.2), EN/UVLO tapped at + **SCHEMATIC DONE 2026-10-02 (netlist + ERC verified) — PCB PLACEMENT + AND ROUTING STILL TO DO.** TI 3-resistor ladder (§8.2.3.2), EN/UVLO tapped at R1–R2 and OVLO at R2–R3, plus an ILIM correction: R46 620 k -> **150 k** (C93947) R1, top: 12V_RAW -> EN/UVLO R47 100 k -> **10 k** (C25744) R2: EN/UVLO -> OVLO R48 NEW -> **12 k** (C25752) \ R3 = 14.2 k in series, R49 NEW -> **2.2 k** (C25879) / OVLO -> GND R45 100 k -> **33 k** (C25779) ILIM 0.52 A -> 1.52 A - U13 pin 2 (OVLO): disconnect from GND, wire to the R47/R48 junction. + U13 pin 2 (OVLO): disconnected from GND, now on net EFUSE_OVLO. + Verified after the edit: nets are 12V_RAW(R46.1) / EFUSE_EN(R46.2, R47.1, + U13.5) / EFUSE_OVLO(R47.2, R48.1, U13.2) / EFUSE_R3MID(R48.2, R49.1) / + GND(R49.2, R45.2, U13.4); component count 150 -> 152 with nothing + dropped; ERC 0 violations. **PCB TODO:** place R48/R49 near U13, route + the new EFUSE_OVLO and EFUSE_R3MID nets, and re-export BOM + CPL + (reapplying CPL_ROTATIONS.md afterwards). Gives UVLO 8.93 V typ (unchanged from today) and OVLO 15.21 V typ, 15.81 V worst case — under U3's 17 V input rating, which is what actually caps the OVLO target. ILIM must exceed the board's own 621 mA inrush; diff --git a/hardware/re-bba-rb/exi.kicad_sch b/hardware/re-bba-rb/exi.kicad_sch index 6e77c94..b9a35cd 100644 --- a/hardware/re-bba-rb/exi.kicad_sch +++ b/hardware/re-bba-rb/exi.kicad_sch @@ -2182,7 +2182,7 @@ (justify left) ) ) - (property "Value" "100k" + (property "Value" "33k" (at 142.24 58.42 0) (show_name no) (do_not_autoplace no) @@ -2226,7 +2226,7 @@ ) ) ) - (property "MPN" "0402WGF1003TCE" + (property "MPN" "0402WGF3302TCE" (at 139.7 58.42 0) (hide yes) (show_name no) @@ -2248,7 +2248,7 @@ ) ) ) - (property "LCSC" "C25741" + (property "LCSC" "C25779" (at 139.7 58.42 0) (hide yes) (show_name no) @@ -2902,83 +2902,6 @@ ) ) ) - (symbol - (lib_id "power:GND") - (at 109.22 53.34 0) - (unit 1) - (body_style 1) - (exclude_from_sim no) - (in_bom yes) - (on_board yes) - (in_pos_files yes) - (dnp no) - (uuid "2c93259d-50ac-44b6-9397-ffe9a4b3bf06") - (property "Reference" "#PWR017" - (at 109.22 57.15 0) - (hide yes) - (show_name no) - (do_not_autoplace no) - (effects - (font - (size 1.27 1.27) - ) - ) - ) - (property "Value" "GND" - (at 109.22 55.626 0) - (show_name no) - (do_not_autoplace no) - (effects - (font - (size 1.27 1.27) - ) - ) - ) - (property "Footprint" "" - (at 109.22 53.34 0) - (hide yes) - (show_name no) - (do_not_autoplace no) - (effects - (font - (size 1.27 1.27) - ) - ) - ) - (property "Datasheet" "" - (at 109.22 53.34 0) - (hide yes) - (show_name no) - (do_not_autoplace no) - (effects - (font - (size 1.27 1.27) - ) - ) - ) - (property "Description" "Power symbol creates a global label with name \"GND\" , ground" - (at 109.22 53.34 0) - (hide yes) - (show_name no) - (do_not_autoplace no) - (effects - (font - (size 1.27 1.27) - ) - ) - ) - (pin "1" - (uuid "5eda44f2-f22c-4a04-9a9c-8cf70f7b115e") - ) - (instances - (project "re-bba-rb" - (path "/dbb182a6-d579-468e-b98b-6f0950da9e3a/1b071f68-b4ea-469c-942f-de06380c9077" - (reference "#PWR017") - (unit 1) - ) - ) - ) - ) (symbol (lib_id "Device:C") (at 91.44 44.45 0) @@ -3814,7 +3737,7 @@ (justify left) ) ) - (property "Value" "100k" + (property "Value" "10k" (at 102.87 54.61 0) (show_name no) (do_not_autoplace no) @@ -3858,7 +3781,7 @@ ) ) ) - (property "MPN" "0402WGF1003TCE" + (property "MPN" "0402WGF1002TCE" (at 100.33 54.61 0) (hide yes) (show_name no) @@ -3880,7 +3803,7 @@ ) ) ) - (property "LCSC" "C25741" + (property "LCSC" "C25744" (at 100.33 54.61 0) (hide yes) (show_name no) @@ -3891,7 +3814,7 @@ ) ) ) - (property "Tolerance" "1%" + (property "Tolerance" "5%" (at 100.33 54.61 0) (hide yes) (show_name no) @@ -3917,83 +3840,6 @@ ) ) ) - (symbol - (lib_id "power:GND") - (at 100.33 58.42 0) - (unit 1) - (body_style 1) - (exclude_from_sim no) - (in_bom yes) - (on_board yes) - (in_pos_files yes) - (dnp no) - (uuid "af4aa082-a85b-49fc-b01d-ec1f4d861d22") - (property "Reference" "#PWR051" - (at 100.33 62.23 0) - (hide yes) - (show_name no) - (do_not_autoplace no) - (effects - (font - (size 1.27 1.27) - ) - ) - ) - (property "Value" "GND" - (at 100.33 60.706 0) - (show_name no) - (do_not_autoplace no) - (effects - (font - (size 1.27 1.27) - ) - ) - ) - (property "Footprint" "" - (at 100.33 58.42 0) - (hide yes) - (show_name no) - (do_not_autoplace no) - (effects - (font - (size 1.27 1.27) - ) - ) - ) - (property "Datasheet" "" - (at 100.33 58.42 0) - (hide yes) - (show_name no) - (do_not_autoplace no) - (effects - (font - (size 1.27 1.27) - ) - ) - ) - (property "Description" "Power symbol creates a global label with name \"GND\" , ground" - (at 100.33 58.42 0) - (hide yes) - (show_name no) - (do_not_autoplace no) - (effects - (font - (size 1.27 1.27) - ) - ) - ) - (pin "1" - (uuid "34503ebf-ec7e-4d2d-b03a-ea208b805468") - ) - (instances - (project "re-bba-rb" - (path "/dbb182a6-d579-468e-b98b-6f0950da9e3a/1b071f68-b4ea-469c-942f-de06380c9077" - (reference "#PWR051") - (unit 1) - ) - ) - ) - ) (symbol (lib_id "power:GND") (at 91.44 48.26 0) @@ -4168,7 +4014,7 @@ (justify left) ) ) - (property "Value" "620k" + (property "Value" "150k" (at 102.87 44.45 0) (show_name no) (do_not_autoplace no) @@ -4212,7 +4058,7 @@ ) ) ) - (property "MPN" "RC0402FR-07620KL" + (property "MPN" "RC0402FR-07150KL" (at 100.33 44.45 0) (hide yes) (show_name no) @@ -4234,7 +4080,7 @@ ) ) ) - (property "LCSC" "C137952" + (property "LCSC" "C93947" (at 100.33 44.45 0) (hide yes) (show_name no) @@ -4642,6 +4488,383 @@ ) ) ) + (label "EFUSE_OVLO" + (at 109.22 53.34 0) + (effects + (font + (size 1.27 1.27) + ) + (justify left bottom) + ) + (uuid "c98beb59-c540-4446-afa1-e8efd402373d") + ) + (label "EFUSE_OVLO" + (at 100.33 58.42 0) + (effects + (font + (size 1.27 1.27) + ) + (justify left bottom) + ) + (uuid "9083df2c-23b3-47c8-b992-6128bb58f6d1") + ) + (symbol + (lib_id "Device:R") + (at 100.33 66.04 0) + (unit 1) + (body_style 1) + (exclude_from_sim no) + (in_bom yes) + (on_board yes) + (in_pos_files yes) + (dnp no) + (uuid "ecf1573b-3b47-4fef-a2f4-2c05176a8cae") + (property "Reference" "R48" + (at 102.87 63.5 0) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + (justify left) + ) + ) + (property "Value" "12k" + (at 102.87 66.04 0) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + (justify left) + ) + ) + (property "Footprint" "Resistor_SMD:R_0402_1005Metric_Pad0.72x0.64mm_HandSolder" + (at 100.33 66.04 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (property "Datasheet" "" + (at 100.33 66.04 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (property "Description" "" + (at 100.33 66.04 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (property "MPN" "0402WGF1202TCE" + (at 100.33 66.04 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (property "Manufacturer" "UNI-ROYAL" + (at 100.33 66.04 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (property "LCSC" "C25752" + (at 100.33 66.04 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (property "Tolerance" "1%" + (at 100.33 66.04 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (pin "1" + (uuid "b2518561-8e15-43c1-9c63-75ca9b526acc") + ) + (pin "2" + (uuid "418fa72b-c982-4837-a130-fb0be84adb62") + ) + (instances + (project "re-bba-rb" + (path "/dbb182a6-d579-468e-b98b-6f0950da9e3a/1b071f68-b4ea-469c-942f-de06380c9077" + (reference "R48") + (unit 1) + ) + ) + ) + ) + (label "EFUSE_OVLO" + (at 100.33 62.23 0) + (effects + (font + (size 1.27 1.27) + ) + (justify left bottom) + ) + (uuid "bde2b3a7-a722-4200-a0ee-ee55a2f62b0c") + ) + (label "EFUSE_R3MID" + (at 100.33 69.85 0) + (effects + (font + (size 1.27 1.27) + ) + (justify left bottom) + ) + (uuid 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