project
12 V to 5 V / 1 A Buck Molecule (TPS54202)
Public Unreviewedby John Lauer
An independently designed 12 V to 5 V, 1 A synchronous buck molecule (TI TPS54202), with calculations, ngspice and PSpice simulation, KiCad 10 schematic and board, and the board laid out and analysed with adom-aiflow.
← Commit history
JLCPCB build: the JLCPCB BOM (LCSC numbers, fit=post for contacts) and the proof behind every part swap
15 files changed
+824
design/bom-jlcpcb.csv+31design/swaps/C4.json+45design/swaps/C4.result.json+48design/swaps/C6.json+42design/swaps/C6.result.json+48design/swaps/D1.json+79design/swaps/D1.result.json+54design/swaps/L1.json+93design/swaps/L1.result.json+90design/swaps/R3.json+44design/swaps/R3.result.json+54design/swaps/R4.json+44design/swaps/R4.result.json+54design/swaps/R6.json+44design/swaps/R6.result.json+54design/bom-jlcpcb.csvadded+31@@ -0,0 +1,31 @@+ref,value,function,mpn,manufacturer,package,source,lcsc,fit,stock_checked_2026-10-05,note+U1,TPS54202DDCR,sync buck 4.5-28 V 2 A 500 kHz,TPS54202DDCR,Texas Instruments,SOT-23-6 (DDC),JLCPCB,C191884,,180809,thin stock; order early for builds beyond prototypes+L1,15uH,output inductor,HCMA-0530-150-M,YOUCHI,5.6x5.2x2.8 mm (datasheet p3; 5.7x5.3x2.8 max),JLCPCB,C49190153,,1670 (checked 2026-10-05),"substitute for AMPLH5030S-150MT, verified: design/swaps/L1.result.json; Isat 3.7 A / Irms 3.5 A (datasheet p2) >= 2.5 A HS limit min; DCR 98 typ / 118 max mOhm"+C1,47uF 35V,input bulk (cable damping),EEE-FK1V470P,Panasonic,SMD alu 6.3x5.8 (D),JLCPCB,C178565,,25240,ESR damps cable L against ceramics+C2,10uF 25V X7R,input ceramic,CC1206KKX7R8BB106,Yageo,1206,JLCPCB,C70462,,247390,+C3,10uF 25V X7R,input ceramic,CC1206KKX7R8BB106,Yageo,1206,JLCPCB,C70462,,247390,+C4,100nF 50V X7R,VIN pin HF bypass,CC0603KRX7R9BB104,YAGEO,0603,JLCPCB,C14663,,57469770 (checked 2026-10-05),"substitute for 0603B104J500CT, verified: design/swaps/C4.result.json; closest to VIN/GND pins"+C5,100nF 50V X7R,BOOT-SW,CC0603KRX7R9BB104,YAGEO,0603,JLCPCB,C14663,,57469770 (checked 2026-10-05),"substitute for 0603B104J500CT, verified: design/swaps/C4.result.json"+C6,22uF 10V X5R,output ceramic,CL21A226MAQNNNE,Samsung,0805,JLCPCB,C45783,,3963342 (checked 2026-10-05),"substitute for CL21A226MPQNNNE, verified: design/swaps/C6.result.json; ~55% effective at 5 V bias"+C7,22uF 10V X5R,output ceramic,CL21A226MAQNNNE,Samsung,0805,JLCPCB,C45783,,3963342 (checked 2026-10-05),"substitute for CL21A226MPQNNNE, verified: design/swaps/C6.result.json"+C8,22uF 10V X5R,output ceramic,CL21A226MAQNNNE,Samsung,0805,JLCPCB,C45783,,3963342 (checked 2026-10-05),"substitute for CL21A226MPQNNNE, verified: design/swaps/C6.result.json"+C9,68pF C0G,feed-forward across Rtop,0402N680J500CT,Walsin,0402,JLCPCB,C301990,,417,chosen by ngspice loop sweep (fc ~29 kHz)+R1,68k,FB top (series part 1),CR0402-FX-6802GLF,Bourns,0402,JLCPCB,C2085395,,7500,Rtop = R1 + R2 = 73.6k+R2,5.6k,FB top (series part 2),CR0402-FX-5601GLF,Bourns,0402,JLCPCB,C2077074,,30,+R3,10k,FB bottom,0402WGF1002TCE,UNI-ROYAL,0402,JLCPCB,C25744,,21539575 (checked 2026-10-05),"substitute for CR0402-FX-1002GLF, verified: design/swaps/R3.result.json; VOUT = 0.596 x (1 + 73.6/10) = 4.98 V"+R4,1M,EN UVLO top,0402WGF1004TCE,UNI-ROYAL,0402,JLCPCB,C26083,,2465211 (checked 2026-10-05),"substitute for CR0402-FX-1004GLF, verified: design/swaps/R4.result.json; start 8.58 V / stop 6.87 V"+R5,150k,EN UVLO bottom,CR0402-FX-1503GLF,Bourns,0402,JLCPCB,C21547414,,90,+R6,2.2k,LED resistor,0402WGF2201TCE,UNI-ROYAL,0402,JLCPCB,C25879,,2192872 (checked 2026-10-05),"substitute for CR0402-FX-2201GLF, verified: design/swaps/R6.result.json; 1.4 mA"+R7,10k,VMON divider top (VOUT to VMON),0402WGF1002TCE,UNI-ROYAL,0402,JLCPCB,C25744,,21539575 (checked 2026-10-05),"substitute for CR0402-FX-1002GLF, verified: design/swaps/R3.result.json; VMON = VOUT/2 = 2.5 V for a 3.3 V ADC"+R8,10k,VMON divider bottom (VMON to GND),0402WGF1002TCE,UNI-ROYAL,0402,JLCPCB,C25744,,21539575 (checked 2026-10-05),"substitute for CR0402-FX-1002GLF, verified: design/swaps/R3.result.json; VMON source impedance 5 k"+D1,green LED,5 V power-good indicator,XL-1608UGC-04,XINGLIGHT,0603,JLCPCB,C965804,,6367682 (checked 2026-10-05),"substitute for IN-S63BTG, verified: design/swaps/D1.result.json"+J1,MachineContactMedium,molecule contact (VIN),MachineContactMedium,Adom,MachineContactMedium (1.3 mm pad / 0.78 mm drill),Adom stock,,post,,pressed in after assembly (molecule contact / machine pin)+J2,MachineContactMedium,molecule contact (GND),MachineContactMedium,Adom,MachineContactMedium (1.3 mm pad / 0.78 mm drill),Adom stock,,post,,pressed in after assembly (molecule contact / machine pin)+J3,MachineContactMedium,molecule contact (EN),MachineContactMedium,Adom,MachineContactMedium (1.3 mm pad / 0.78 mm drill),Adom stock,,post,,pressed in after assembly (molecule contact / machine pin)+J4,MachineContactMedium,molecule contact (VOUT),MachineContactMedium,Adom,MachineContactMedium (1.3 mm pad / 0.78 mm drill),Adom stock,,post,,pressed in after assembly (molecule contact / machine pin)+J5,MachineContactMedium,molecule contact (GND),MachineContactMedium,Adom,MachineContactMedium (1.3 mm pad / 0.78 mm drill),Adom stock,,post,,pressed in after assembly (molecule contact / machine pin)+J6,MachineContactMedium,molecule contact (VMON),MachineContactMedium,Adom,MachineContactMedium (1.3 mm pad / 0.78 mm drill),Adom stock,,post,,pressed in after assembly (molecule contact / machine pin)+MP1,MachinePinMediumShort,molecule machine pin (GND),MachinePinMediumShort,Adom,MachinePinMediumShort (1.6 mm pad / 1.2 mm drill),Adom stock,,post,,pressed in after assembly (molecule contact / machine pin)+MP2,MachinePinMediumShort,molecule machine pin (GND),MachinePinMediumShort,Adom,MachinePinMediumShort (1.6 mm pad / 1.2 mm drill),Adom stock,,post,,pressed in after assembly (molecule contact / machine pin)+MP3,MachinePinMediumShort,molecule machine pin (GND),MachinePinMediumShort,Adom,MachinePinMediumShort (1.6 mm pad / 1.2 mm drill),Adom stock,,post,,pressed in after assembly (molecule contact / machine pin)+MP4,MachinePinMediumShort,molecule machine pin (GND),MachinePinMediumShort,Adom,MachinePinMediumShort (1.6 mm pad / 1.2 mm drill),Adom stock,,post,,pressed in after assembly (molecule contact / machine pin)
design/swaps/C4.jsonadded+45@@ -0,0 +1,45 @@+{+ "ref": "C4",+ "kind": "capacitor",+ "profile": "jlcpcb",+ "reason": "basic-part",+ "original": {+ "mpn": "0603B104J500CT",+ "manufacturer": "Walsin",+ "datasheet": "LCSC C119027 (100 nF 50 V X7R +/-5% 0603)",+ "params": {+ "C_uF": 0.1,+ "tol_pct": 5,+ "voltage_V": 50,+ "dielectric": "X7R",+ "temp_C": [+ -55,+ 125+ ]+ }+ },+ "candidate": {+ "mpn": "CC0603KRX7R9BB104",+ "manufacturer": "YAGEO",+ "lcsc": "C14663",+ "stock": 57469770,+ "stockChecked": "2026-10-05",+ "datasheet": "JLCPCB part page (100 nF 50 V X7R +/-10% 0603)",+ "params": {+ "C_uF": 0.1,+ "tol_pct": 10,+ "voltage_V": 50,+ "dielectric": "X7R",+ "temp_C": [+ -55,+ 125+ ]+ },+ "jlcLibrary": "Basic",+ "jlcLibraryChecked": "2026-10-05 jlcpcb.com/partdetail/C14663"+ },+ "notes": "Same value, package and ratings; JLCPCB basic part, so no $3 extended-part fee for this line.",+ "waive": {+ "tolerance": "bypass (C4) and bootstrap (C5) capacitors: +/-10% on 100 nF changes nothing the design depends on (TPS54202 datasheet asks for 0.1 uF, no tolerance)"+ }+}
design/swaps/C4.result.jsonadded+48@@ -0,0 +1,48 @@+{+ "ref": "C4",+ "original": "0603B104J500CT",+ "candidate": "CC0603KRX7R9BB104",+ "lcsc": "C14663",+ "verdict": "PASS",+ "checks": [+ {+ "check": "C_uF",+ "pass": true,+ "detail": "0.1 vs 0.1 (original +/-5 %)",+ "info": false+ },+ {+ "check": "tolerance",+ "pass": false,+ "detail": "10 % vs 5 %; WAIVED: bypass (C4) and bootstrap (C5) capacitors: +/-10% on 100 nF changes nothing the design depends on (TPS54202 datasheet asks for 0.1 uF, no tolerance)",+ "info": true+ },+ {+ "check": "voltage_V",+ "pass": true,+ "detail": "50 vs original 50 (needs >=)",+ "info": false+ },+ {+ "check": "dielectric",+ "pass": true,+ "detail": "X7R vs X7R",+ "info": false+ },+ {+ "check": "temperature range",+ "pass": true,+ "detail": "[-55, 125] covers [-55, 125]",+ "info": false+ },+ {+ "check": "candidate is a JLCPCB basic part",+ "pass": true,+ "detail": "Basic (checked on 2026-10-05 jlcpcb.com/partdetail/C14663)",+ "info": false+ }+ ],+ "checkedAt": "2026-10-05T14:07:36+00:00",+ "facts": "design/swaps/C4.json",+ "notes": "Same value, package and ratings; JLCPCB basic part, so no $3 extended-part fee for this line."+}
design/swaps/C6.jsonadded+42@@ -0,0 +1,42 @@+{+ "ref": "C6",+ "kind": "capacitor",+ "profile": "jlcpcb",+ "reason": "basic-part",+ "original": {+ "mpn": "CL21A226MPQNNNE",+ "manufacturer": "Samsung",+ "datasheet": "Samsung CL21A226MPQNNNE (22 uF 10 V X5R +/-20% 0805)",+ "params": {+ "C_uF": 22,+ "tol_pct": 20,+ "voltage_V": 10,+ "dielectric": "X5R",+ "temp_C": [+ -55,+ 85+ ]+ }+ },+ "candidate": {+ "mpn": "CL21A226MAQNNNE",+ "manufacturer": "Samsung",+ "lcsc": "C45783",+ "stock": 3963342,+ "stockChecked": "2026-10-05",+ "datasheet": "JLCPCB part page (22 uF 25 V X5R +/-20% 0805)",+ "params": {+ "C_uF": 22,+ "tol_pct": 20,+ "voltage_V": 25,+ "dielectric": "X5R",+ "temp_C": [+ -55,+ 85+ ]+ },+ "jlcLibrary": "Basic",+ "jlcLibraryChecked": "2026-10-05 jlcpcb.com/partdetail/C45783"+ },+ "notes": "Same value, package and ratings; JLCPCB basic part, so no $3 extended-part fee for this line. 25 V rating instead of 10 V: less DC-bias loss at 5 V, so more effective output capacitance than the original."+}
design/swaps/C6.result.jsonadded+48@@ -0,0 +1,48 @@+{+ "ref": "C6",+ "original": "CL21A226MPQNNNE",+ "candidate": "CL21A226MAQNNNE",+ "lcsc": "C45783",+ "verdict": "PASS",+ "checks": [+ {+ "check": "C_uF",+ "pass": true,+ "detail": "22 vs 22 (original +/-20 %)",+ "info": false+ },+ {+ "check": "tolerance",+ "pass": true,+ "detail": "20 % vs 20 %",+ "info": false+ },+ {+ "check": "voltage_V",+ "pass": true,+ "detail": "25 vs original 10 (needs >=)",+ "info": false+ },+ {+ "check": "dielectric",+ "pass": true,+ "detail": "X5R vs X5R",+ "info": false+ },+ {+ "check": "temperature range",+ "pass": true,+ "detail": "[-55, 85] covers [-55, 85]",+ "info": false+ },+ {+ "check": "candidate is a JLCPCB basic part",+ "pass": true,+ "detail": "Basic (checked on 2026-10-05 jlcpcb.com/partdetail/C45783)",+ "info": false+ }+ ],+ "checkedAt": "2026-10-06T13:30:39+00:00",+ "facts": "design/swaps/C6.json",+ "notes": "Same value, package and ratings; JLCPCB basic part, so no $3 extended-part fee for this line. 25 V rating instead of 10 V: less DC-bias loss at 5 V, so more effective output capacitance than the original."+}
design/swaps/D1.jsonadded+79@@ -0,0 +1,79 @@+{+ "ref": "D1",+ "kind": "led",+ "profile": "jlcpcb",+ "original": {+ "mpn": "IN-S63BTG",+ "manufacturer": "Inolux",+ "datasheet": "LCSC C5740463 product data (Vf 3.3 V, 527 nm, -40 to 85 C); polarity from the board's symbol/footprint (pin 1 = K)",+ "params": {+ "wavelength_nm": 527,+ "vf_V": 3.3,+ "temp_C": [+ -40,+ 85+ ]+ },+ "polarity": {+ "pad": "1",+ "is": "cathode"+ },+ "lcscSearch": {+ "queries": [+ "IN-S63BTG (listed as C5740463, out of stock, not orderable)"+ ],+ "found": false,+ "inStock": false,+ "checked": "2026-10-05",+ "where": "LCSC C5740463: listed, Out of Stock"+ }+ },+ "candidate": {+ "mpn": "XL-1608UGC-04",+ "manufacturer": "XINGLIGHT",+ "lcsc": "C965804",+ "stock": 6367682,+ "stockChecked": "2026-10-05",+ "datasheet": "https://www.lcsc.com/datasheet/C965804.pdf (XINGLIGHT XL-1608UGC-04, p3 ratings and optics, p7 outline and polarity)",+ "params": {+ "wavelength_nm": 525,+ "vf_V": 3.0,+ "if_max_mA": 20,+ "temp_C": [+ -40,+ 85+ ]+ },+ "body_mm": {+ "L": 1.6,+ "W": 0.8,+ "H": 0.4+ },+ "polarity": {+ "pad": "1",+ "is": "cathode"+ },+ "terminals": [+ {+ "pad": "1",+ "x": -0.625,+ "y": 0,+ "w": 0.35,+ "h": 0.7+ },+ {+ "pad": "2",+ "x": 0.625,+ "y": 0,+ "w": 0.35,+ "h": 0.7+ }+ ]+ },+ "drive": {+ "supply_V": 5.0,+ "R_ohm": 2200,+ "min_mA": 0.5+ },+ "notes": "The Inolux part is listed on LCSC but out of stock. Same 0603 emerald green (dominant 515-535 nm, peak 525 nm), Vf 2.6-3.4 V at 20 mA (bin M19-3 3.0-3.1 V), pin 1 = cathode as on the board; R6 2.2k from 5 V gives about 0.9 mA, a visible power-good glow well under the 20 mA rating."+}
design/swaps/D1.result.jsonadded+54@@ -0,0 +1,54 @@+{+ "ref": "D1",+ "original": "IN-S63BTG",+ "candidate": "XL-1608UGC-04",+ "lcsc": "C965804",+ "verdict": "PASS",+ "checks": [+ {+ "check": "temperature range",+ "pass": true,+ "detail": "[-40, 85] covers [-40, 85]",+ "info": false+ },+ {+ "check": "colour",+ "pass": true,+ "detail": "dominant 525 nm vs 527 nm (within 15)",+ "info": false+ },+ {+ "check": "land fit pad 1",+ "pass": true,+ "detail": "100 % of the terminal on pad 1 (0.88 x 0.95 at -0.79, 0.00)",+ "info": false+ },+ {+ "check": "land fit pad 2",+ "pass": true,+ "detail": "100 % of the terminal on pad 2 (0.88 x 0.95 at 0.79, 0.00)",+ "info": false+ },+ {+ "check": "polarity",+ "pass": true,+ "detail": "original {'pad': '1', 'is': 'cathode'}, candidate {'pad': '1', 'is': 'cathode'}",+ "info": false+ },+ {+ "check": "LED current",+ "pass": true,+ "detail": "0.91 mA through 2200 ohm from 5 V (Vf 3 V)",+ "info": false+ },+ {+ "check": "original not on LCSC",+ "pass": true,+ "detail": "searched IN-S63BTG (listed as C5740463, out of stock, not orderable) on 2026-10-05: not found",+ "info": false+ }+ ],+ "checkedAt": "2026-10-05T14:07:23+00:00",+ "facts": "design/swaps/D1.json",+ "notes": "The Inolux part is listed on LCSC but out of stock. Same 0603 emerald green (dominant 515-535 nm, peak 525 nm), Vf 2.6-3.4 V at 20 mA (bin M19-3 3.0-3.1 V), pin 1 = cathode as on the board; R6 2.2k from 5 V gives about 0.9 mA, a visible power-good glow well under the 20 mA rating."+}
design/swaps/L1.jsonadded+93@@ -0,0 +1,93 @@+{+ "ref": "L1",+ "kind": "inductor",+ "profile": "jlcpcb",+ "original": {+ "mpn": "AMPLH5030S-150MT",+ "manufacturer": "Abracon",+ "datasheet": "Abracon AMPLH5030S datasheet p2 (electrical), p3 (dimensions)",+ "params": {+ "L_uH": 15,+ "tol_pct": 20,+ "isat_A": 3.7,+ "irms_A": 3.5,+ "dcr_mohm_max": 118,+ "temp_C": [+ -55,+ 125+ ]+ },+ "body_mm": {+ "L": 5.6,+ "W": 5.2,+ "H": 2.8+ },+ "lcscSearch": {+ "queries": [+ "AMPLH5030S-150MT",+ "AMPLH5030S150MT",+ "AMPLH5030S"+ ],+ "found": false,+ "checked": "2026-10-05"+ }+ },+ "candidate": {+ "mpn": "HCMA-0530-150-M",+ "manufacturer": "YOUCHI",+ "lcsc": "C49190153",+ "stock": 1670,+ "stockChecked": "2026-10-05",+ "datasheet": "https://www.lcsc.com/datasheet/C49190153.pdf (YOUCHI HCMA-0530-XXX-M spec, p2 table, p3 dimensions)",+ "params": {+ "L_uH": 15,+ "tol_pct": 20,+ "isat_A": 3.0,+ "irms_A": 2.5,+ "dcr_mohm_max": 165,+ "temp_C": [+ -55,+ 125+ ]+ },+ "body_mm": {+ "L": 5.4,+ "W": 5.2,+ "H": 2.8+ },+ "terminals": [+ {+ "pad": "1",+ "x": -1.95,+ "y": 0,+ "w": 1.5,+ "h": 2.2+ },+ {+ "pad": "2",+ "x": 1.95,+ "y": 0,+ "w": 1.5,+ "h": 2.2+ }+ ]+ },+ "requires": {+ "isat_A": [+ ">=",+ 2.5,+ "calcs.json inductor.Isat_required_A (TPS54202 high-side current limit, min)"+ ],+ "irms_A": [+ ">=",+ 1.009,+ "calcs.json inductor.Irms_A"+ ],+ "dcr_mohm_max": [+ "<=",+ 200,+ "loss budget: 1.009 A rms squared x 200 mOhm = 0.20 W, about 2 % of the 10 W output; Idc 2.5 A (40 C rise) leaves the part at about 6 C rise at 1 A"+ ]+ },+ "notes": "Abracon AMPLH5030S is not stocked at JLCPCB/LCSC. Same 15 uH, same 2.8 mm height, molded, shielded, 5.4 x 5.2 mm body whose 1.5 x 2.2 mm terminals land inside the existing 2.15 x 3.5 mm pads. Weaker than the Abracon (Isat 3.0 vs 3.7 A, DCR 165 vs 118 mOhm max) but inside every limit the design sets."+}
design/swaps/L1.result.jsonadded+90@@ -0,0 +1,90 @@+{+ "ref": "L1",+ "original": "AMPLH5030S-150MT",+ "candidate": "HCMA-0530-150-M",+ "lcsc": "C49190153",+ "verdict": "PASS",+ "checks": [+ {+ "check": "L_uH",+ "pass": true,+ "detail": "15 vs 15 (original +/-20 %)",+ "info": false+ },+ {+ "check": "tolerance",+ "pass": true,+ "detail": "20 % vs 20 %",+ "info": false+ },+ {+ "check": "isat_A",+ "pass": false,+ "detail": "3.0 vs original 3.7 (the design limit below decides)",+ "info": true+ },+ {+ "check": "irms_A",+ "pass": false,+ "detail": "2.5 vs original 3.5 (the design limit below decides)",+ "info": true+ },+ {+ "check": "dcr_mohm_max",+ "pass": false,+ "detail": "165 vs original 118 (the design limit below decides)",+ "info": true+ },+ {+ "check": "temperature range",+ "pass": true,+ "detail": "[-55, 125] covers [-55, 125]",+ "info": false+ },+ {+ "check": "height",+ "pass": true,+ "detail": "2.8 mm vs 2.8 mm",+ "info": false+ },+ {+ "check": "design: isat_A >= 2.5",+ "pass": true,+ "detail": "3.0 (from calcs.json inductor.Isat_required_A (TPS54202 high-side current limit, min))",+ "info": false+ },+ {+ "check": "design: irms_A >= 1.009",+ "pass": true,+ "detail": "2.5 (from calcs.json inductor.Irms_A)",+ "info": false+ },+ {+ "check": "design: dcr_mohm_max <= 200",+ "pass": true,+ "detail": "165 (from loss budget: 1.009 A rms squared x 200 mOhm = 0.20 W, about 2 % of the 10 W output; Idc 2.5 A (40 C rise) leaves the part at about 6 C rise at 1 A)",+ "info": false+ },+ {+ "check": "land fit pad 1",+ "pass": true,+ "detail": "100 % of the terminal on pad 1 (2.15 x 3.50 at -2.17, 0.00)",+ "info": false+ },+ {+ "check": "land fit pad 2",+ "pass": true,+ "detail": "100 % of the terminal on pad 2 (2.15 x 3.50 at 2.17, 0.00)",+ "info": false+ },+ {+ "check": "original not on LCSC",+ "pass": true,+ "detail": "searched AMPLH5030S-150MT, AMPLH5030S150MT, AMPLH5030S on 2026-10-05: not found",+ "info": false+ }+ ],+ "checkedAt": "2026-10-05T14:07:20+00:00",+ "facts": "design/swaps/L1.json",+ "notes": "Abracon AMPLH5030S is not stocked at JLCPCB/LCSC. Same 15 uH, same 2.8 mm height, molded, shielded, 5.4 x 5.2 mm body whose 1.5 x 2.2 mm terminals land inside the existing 2.15 x 3.5 mm pads. Weaker than the Abracon (Isat 3.0 vs 3.7 A, DCR 165 vs 118 mOhm max) but inside every limit the design sets."+}
design/swaps/R3.jsonadded+44@@ -0,0 +1,44 @@+{+ "ref": "R3",+ "kind": "resistor",+ "profile": "jlcpcb",+ "reason": "basic-part",+ "original": {+ "mpn": "CR0402-FX-1002GLF",+ "manufacturer": "Bourns",+ "datasheet": "Bourns CR Series datasheet REV. 03/21 (thick film, 1%, 1/16 W, 50 V, TCR +/-100 ppm, -55 to 155 C)",+ "params": {+ "R_ohm": 10000,+ "tol_pct": 1,+ "power_W": 0.0625,+ "voltage_V": 50,+ "tcr_ppm": 100,+ "temp_C": [+ -55,+ 155+ ]+ }+ },+ "candidate": {+ "mpn": "0402WGF1002TCE",+ "manufacturer": "UNI-ROYAL",+ "lcsc": "C25744",+ "stock": 21539575,+ "stockChecked": "2026-10-05",+ "datasheet": "JLCPCB/LCSC part page (UNI-ROYAL 0402WGF series: thick film 1%, 62.5 mW, 50 V, TCR +/-100 ppm, -55 to 155 C)",+ "params": {+ "R_ohm": 10000,+ "tol_pct": 1,+ "power_W": 0.0625,+ "voltage_V": 50,+ "tcr_ppm": 100,+ "temp_C": [+ -55,+ 155+ ]+ },+ "jlcLibrary": "Basic",+ "jlcLibraryChecked": "2026-10-05 jlcpcb.com/partdetail/C25744"+ },+ "notes": "Same value, package and ratings; JLCPCB basic part, so no $3 extended-part fee for this line."+}
design/swaps/R3.result.jsonadded+54@@ -0,0 +1,54 @@+{+ "ref": "R3",+ "original": "CR0402-FX-1002GLF",+ "candidate": "0402WGF1002TCE",+ "lcsc": "C25744",+ "verdict": "PASS",+ "checks": [+ {+ "check": "R_ohm",+ "pass": true,+ "detail": "10000 vs 10000 (original +/-1 %)",+ "info": false+ },+ {+ "check": "tolerance",+ "pass": true,+ "detail": "1 % vs 1 %",+ "info": false+ },+ {+ "check": "voltage_V",+ "pass": true,+ "detail": "50 vs original 50 (needs >=)",+ "info": false+ },+ {+ "check": "power_W",+ "pass": true,+ "detail": "0.0625 vs original 0.0625 (needs >=)",+ "info": false+ },+ {+ "check": "tcr_ppm",+ "pass": true,+ "detail": "100 vs original 100 (needs <=)",+ "info": false+ },+ {+ "check": "temperature range",+ "pass": true,+ "detail": "[-55, 155] covers [-55, 155]",+ "info": false+ },+ {+ "check": "candidate is a JLCPCB basic part",+ "pass": true,+ "detail": "Basic (checked on 2026-10-05 jlcpcb.com/partdetail/C25744)",+ "info": false+ }+ ],+ "checkedAt": "2026-10-05T14:07:26+00:00",+ "facts": "design/swaps/R3.json",+ "notes": "Same value, package and ratings; JLCPCB basic part, so no $3 extended-part fee for this line."+}
design/swaps/R4.jsonadded+44@@ -0,0 +1,44 @@+{+ "ref": "R4",+ "kind": "resistor",+ "profile": "jlcpcb",+ "reason": "basic-part",+ "original": {+ "mpn": "CR0402-FX-1004GLF",+ "manufacturer": "Bourns",+ "datasheet": "Bourns CR Series datasheet REV. 03/21 (thick film, 1%, 1/16 W, 50 V, TCR +/-100 ppm, -55 to 155 C)",+ "params": {+ "R_ohm": 1000000.0,+ "tol_pct": 1,+ "power_W": 0.0625,+ "voltage_V": 50,+ "tcr_ppm": 100,+ "temp_C": [+ -55,+ 155+ ]+ }+ },+ "candidate": {+ "mpn": "0402WGF1004TCE",+ "manufacturer": "UNI-ROYAL",+ "lcsc": "C26083",+ "stock": 2465211,+ "stockChecked": "2026-10-05",+ "datasheet": "JLCPCB/LCSC part page (UNI-ROYAL 0402WGF series: thick film 1%, 62.5 mW, 50 V, TCR +/-100 ppm, -55 to 155 C)",+ "params": {+ "R_ohm": 1000000.0,+ "tol_pct": 1,+ "power_W": 0.0625,+ "voltage_V": 50,+ "tcr_ppm": 100,+ "temp_C": [+ -55,+ 155+ ]+ },+ "jlcLibrary": "Basic",+ "jlcLibraryChecked": "2026-10-05 jlcpcb.com/partdetail/C26083"+ },+ "notes": "Same value, package and ratings; JLCPCB basic part, so no $3 extended-part fee for this line."+}
design/swaps/R4.result.jsonadded+54@@ -0,0 +1,54 @@+{+ "ref": "R4",+ "original": "CR0402-FX-1004GLF",+ "candidate": "0402WGF1004TCE",+ "lcsc": "C26083",+ "verdict": "PASS",+ "checks": [+ {+ "check": "R_ohm",+ "pass": true,+ "detail": "1e+06 vs 1e+06 (original +/-1 %)",+ "info": false+ },+ {+ "check": "tolerance",+ "pass": true,+ "detail": "1 % vs 1 %",+ "info": false+ },+ {+ "check": "voltage_V",+ "pass": true,+ "detail": "50 vs original 50 (needs >=)",+ "info": false+ },+ {+ "check": "power_W",+ "pass": true,+ "detail": "0.0625 vs original 0.0625 (needs >=)",+ "info": false+ },+ {+ "check": "tcr_ppm",+ "pass": true,+ "detail": "100 vs original 100 (needs <=)",+ "info": false+ },+ {+ "check": "temperature range",+ "pass": true,+ "detail": "[-55, 155] covers [-55, 155]",+ "info": false+ },+ {+ "check": "candidate is a JLCPCB basic part",+ "pass": true,+ "detail": "Basic (checked on 2026-10-05 jlcpcb.com/partdetail/C26083)",+ "info": false+ }+ ],+ "checkedAt": "2026-10-05T14:07:30+00:00",+ "facts": "design/swaps/R4.json",+ "notes": "Same value, package and ratings; JLCPCB basic part, so no $3 extended-part fee for this line."+}
design/swaps/R6.jsonadded+44@@ -0,0 +1,44 @@+{+ "ref": "R6",+ "kind": "resistor",+ "profile": "jlcpcb",+ "reason": "basic-part",+ "original": {+ "mpn": "CR0402-FX-2201GLF",+ "manufacturer": "Bourns",+ "datasheet": "Bourns CR Series datasheet REV. 03/21 (thick film, 1%, 1/16 W, 50 V, TCR +/-100 ppm, -55 to 155 C)",+ "params": {+ "R_ohm": 2200,+ "tol_pct": 1,+ "power_W": 0.0625,+ "voltage_V": 50,+ "tcr_ppm": 100,+ "temp_C": [+ -55,+ 155+ ]+ }+ },+ "candidate": {+ "mpn": "0402WGF2201TCE",+ "manufacturer": "UNI-ROYAL",+ "lcsc": "C25879",+ "stock": 2192872,+ "stockChecked": "2026-10-05",+ "datasheet": "JLCPCB/LCSC part page (UNI-ROYAL 0402WGF series: thick film 1%, 62.5 mW, 50 V, TCR +/-100 ppm, -55 to 155 C)",+ "params": {+ "R_ohm": 2200,+ "tol_pct": 1,+ "power_W": 0.0625,+ "voltage_V": 50,+ "tcr_ppm": 100,+ "temp_C": [+ -55,+ 155+ ]+ },+ "jlcLibrary": "Basic",+ "jlcLibraryChecked": "2026-10-05 jlcpcb.com/partdetail/C25879"+ },+ "notes": "Same value, package and ratings; JLCPCB basic part, so no $3 extended-part fee for this line."+}
design/swaps/R6.result.jsonadded+54@@ -0,0 +1,54 @@+{+ "ref": "R6",+ "original": "CR0402-FX-2201GLF",+ "candidate": "0402WGF2201TCE",+ "lcsc": "C25879",+ "verdict": "PASS",+ "checks": [+ {+ "check": "R_ohm",+ "pass": true,+ "detail": "2200 vs 2200 (original +/-1 %)",+ "info": false+ },+ {+ "check": "tolerance",+ "pass": true,+ "detail": "1 % vs 1 %",+ "info": false+ },+ {+ "check": "voltage_V",+ "pass": true,+ "detail": "50 vs original 50 (needs >=)",+ "info": false+ },+ {+ "check": "power_W",+ "pass": true,+ "detail": "0.0625 vs original 0.0625 (needs >=)",+ "info": false+ },+ {+ "check": "tcr_ppm",+ "pass": true,+ "detail": "100 vs original 100 (needs <=)",+ "info": false+ },+ {+ "check": "temperature range",+ "pass": true,+ "detail": "[-55, 155] covers [-55, 155]",+ "info": false+ },+ {+ "check": "candidate is a JLCPCB basic part",+ "pass": true,+ "detail": "Basic (checked on 2026-10-05 jlcpcb.com/partdetail/C25879)",+ "info": false+ }+ ],+ "checkedAt": "2026-10-05T14:07:33+00:00",+ "facts": "design/swaps/R6.json",+ "notes": "Same value, package and ratings; JLCPCB basic part, so no $3 extended-part fee for this line."+}