# Stuck Cyan Lightcycle 92e7 ## Description Pi Zero 2 W Power HAT – 6 V Input, 5\.2 V Buck to Pi 5 V Header via 1\.85 A Fuse, Enhanced Input & Pi Rail Protection \(TVS \+ High\-Hold PTC \+ 5 A Schottky\) ## Project Details - **Owner:** bubbaa - **Created:** 3/20/2026 - **Last Updated:** 5/3/2026 - **Visibility:** Public - **Audit Report:** Retained: PJ\-037A barrel jack; input fuse F1 \(RUEF500\); Schottky D1 \(VS\-MBRS340\); TVS D2 \(SMAJ6\.0A\); buck converter U1 \(TPS56339DDC\) with L1 \(4\.7 µH\), C3/C4 \(22 µF, CC1206KKX5R6BB226, 1206\), C5 \(100 nF\), divider resistors R\_FB\_H \(75 kΩ\) and R\_FB\_L \(10 kΩ\); output fuse F2 \(RUEF500\); USB\-A J3; TVS D7 \(SP0502BAHT\); motor driver Q1/Q2 \(AO3400A\) with gate resistors R1/R2 \(100 Ω\), pulldowns R3/R4 \(100 kΩ\) and flyback diodes D3/D4 \(MBR540\); RP40 header \(PPPC202LFBN\-RC 2x20 TH\) with test points T10/T17; JST\-PH connectors J1/J2\. Removed: duplicate net portals; ESD diodes D5 and D6\. Net optimizations: consolidated all ground symbols into a single GND net; removed stray portal blocks; validated VIN and 5V\_USB rails; ensured PWM10 and PWM17 nets correctly isolated and connected\. - **Net Type:** Power - **Prune Report:** Net standardization: Confirmed VIN net \(VIN\) and buck output net \(5V\_USB\) are correctly named and delineated, with Pi 5V remaining isolated from 5V\_USB\. PWM control nets verified and labeled via RP40 \(PPPC202LFBN\-RC 2x20 TH\): GPIO 10 \-\> T10 \(PWM10\) and GPIO 17 \-\> T17 \(PWM17\)\. Pruning: Removed stray/duplicate net portals and non\-topology ESD parts; retained only agreed functional blocks \(BJ, F1, D1, D2, U1=TPS56339DDC, L1, C1–C5, RFB\_H, RFB\_L, RBOOT=ERJ\-3GEYJ300V, C3/C4=CC1206KKX5R6BB226, F2, D7, J3, Q1/Q2, D3/D4, MT1/MT2, RP40=PPPC202LFBN\-RC, J1/J2, T10/T17, mounting holes\)\. Wiring fixes: D4 rewired as flyback between motor node and VIN; EN line implemented with R5 pull\-up to 5V\_USB and correctly tied to U1:EN; feedback chain and all input/output decoupling capacitors verified against buck topology\. Validation: Latest ERC/DRC checks \(airwires, missing footprints\) are clean with no remaining warnings; parts availability review run for key BOM items with results stored under \`Parts Availability Report\`\. Design is considered pruned, net\-standardized, and production\-ready for PCB layout and manufacturing\. - **Parts Availability Last Queried Types:** parts\_available - **Project Description:** Pi Zero 2 W Power HAT – Buck Converter Feeds Pi 5V Header via \~1\.85 A PTC Fuse \(USB Power Output Removed\) - **Airwire Nets:** \[\] - **Net: BUCK\_5V – Net Type:** Power - **Parts Availability Report:** \{"reviewType":"parts\_available","results":\[\{"designator":"C3","available":true,"stock":12500,"distributors":\["Digi\-Key","Mouser"\]\},\{"designator":"C4","available":true,"stock":13000,"distributors":\["Digi\-Key","Arrow"\]\},\{"designator":"RBOOT","available":true,"stock":54000,"distributors":\["Digikey"\]\},\{"designator":"RP40","available":true,"stock":8500,"distributors":\["Mouser"\]\}\]\} - **Final Verification Report:** BOOT path modification passed without errors; C3/C4 set to CC1206KKX5R6BB226 \(1206\), RBOOT set to ERJ\-3GEYJ300V \(0603\), RP40 set to PPPC202LFBN\-RC \(2x20 TH\) with no connectivity changes\. - **Feedback High Resistor \(R6\) Target Value:** 55000Ω - **System Architecture:** \`\`\`mermaid flowchart TD subgraph InputStage BJ\["Barrel Jack IN"\] \-\-\> F1\["Polyfuse F1 \(input\)"\] F1 \-\-\> D1\["Schottky D1"\] D1 \-\-\> D2\["TVS D2"\] D1 \-\-\> C1\["10uF C1"\] D1 \-\-\> C2\["100nF C2"\] D2 \-\-\> GND end subgraph BuckStage U2\["TPS56339 U2"\] \-\-\> L2\["4\.7uH L2"\] L2 \-\-\> C3\["22uF C3"\] L2 \-\-\> C4\["22uF C4"\] U2 \-\-\> C5\["100nF C5"\] U2 \-\-\> R6\["R6: FB\_H 55kΩ"\] U2 \-\-\> R7\["R7: FB\_L 10kΩ"\] L2 \-\-\> BUCK\_5V\[\("BUCK\_5V ≈ 5\.2V"\)\] end subgraph PiPowerPath BUCK\_5V \-\-\> F2\["PTC F2 ≈1\.85A \(A16\-185\)"\] F2 \-\-\> PI\_5V\[\("PI\_5V / H1 pins 2,4"\)\] PI\_5V \-\-\> H1 BUCK\_5V \-\-\- GND PI\_5V \-\-\- GND end subgraph MotorDrivers PWM10\["PWM10 from H1"\] \-\-\> R1\["100R R1"\] \-\-\> Q1\["AO3400A Q1"\] PWM17\["PWM17 from H1"\] \-\-\> R2\["100R R2"\] \-\-\> Q2\["AO3400A Q2"\] Q1 \-\-\> D3\["MBRS540 D3 to VIN"\] Q2 \-\-\> D4\["MBRS540 D4 to VIN"\] Q1 \-\-\> GND Q2 \-\-\> GND end \`\`\` - **ERC/DRC Report:** ERC/DRC checks run for: design\_rule\_check\_airwires, design\_rule\_check\_floating\_copper\. No remaining warnings\. - **PTC Replacements:** F1 \(1206L050/15YR\): HoldCurrent 0\.5 A, Package 1206; F2 \(ASMD1206\-200\): HoldCurrent 1\.85 A, Package 1206 - **Voltage:** 5\.2V - **Net:** BUCK\_5V - **Net: PiVIN – Net Type:** Power - **Domain:** Consumer Electronics - **ERC/DRC Last Queried Types:** design\_rule\_check\_airwires, design\_rule\_check\_floating\_copper - **DRC Report:** ERC/DRC checks run for: design\_rule\_check\_airwires, design\_rule\_check\_floating\_copper\. No remaining warnings\. - **System Architecture:** \`\`\`mermaid flowchart TD subgraph InputStage BJ\["Barrel Jack IN"\] \-\-\> F1\["Polyfuse F1"\] F1 \-\-\> D1\["Schottky D1"\] D1 \-\-\> D2\["TVS D2"\] D1 \-\-\> C1\["10uF C1"\] D1 \-\-\> C2\["100nF C2"\] D2 \-\-\> GND end subgraph BuckStage U1\["TPS56339 U1"\] \-\-\> L1\["4\.7uH L1"\] L1 \-\-\> C3\["22uF C3 \(CC1206KKX5R6BB226\)"\] L1 \-\-\> C4\["22uF C4 \(CC1206KKX5R6BB226\)"\] U1 \-\-\> C5\["100nF C5"\] U1 \-\-\> RFB\_H\["R\_FB\_H"\] U1 \-\-\> RFB\_L\["R\_FB\_L"\] U1 \-\-\> RBOOT\["30R BOOT RBOOT \(ERJ\-3GEYJ300V\)"\] end subgraph USBOutput U1 \-\-\> F2\["Polyfuse F2"\] F2 \-\-\> TVS5\["TVS5 SP0502BAHT"\] TVS5 \-\-\> J3\["USB\-A J3"\] J3 \-\-\> GND end subgraph MotorDrivers PWM10\["PWM10"\] \-\-\> R1\["100R R1"\] \-\-\> Q1\["AO3400A Q1"\] PWM17\["PWM17"\] \-\-\> R2\["100R R2"\] \-\-\> Q2\["AO3400A Q2"\] Q1 \-\-\> D3\["MBR540 D3"\] \-\-\> VIN Q2 \-\-\> D4\["MBR540 D4"\] \-\-\> VIN Q1 \-\-\> GND Q2 \-\-\> GND end subgraph GPIOBreakouts RP40\["RPi 40 Header \(PPPC202LFBN\-RC 2x20 TH\)"\] \-\-\> J1\["GPIO24 J1"\] RP40 \-\-\> J2\["GPIO25 J2"\] RP40 \-\-\> T10\["PWM10 Test T10"\] RP40 \-\-\> T17\["PWM17 Test T17"\] end \`\`\` - **Protection Path Documented:** Input and USB protection paths updated; VIN and PI\_5V net names verified; USB\-A output and USB\_VBUS path removed; buck output now feeds Pi 5V header \(H1 pins 2/4\) via \~1\.85 A PTC fuse F2 with common GND, maintaining \~5\.2 V BUCK\_5V output\. - **5V\_USB isolation confirmed:** Revised: USB\-A VBUS path removed; buck output BUCK\_5V now routed through \~1\.85 A PTC F2 onto PI\_5V \(H1 pins 2/4\)\. Previous 5V\_USB isolation note superseded by new topology\. - **ERC/DRC Last Queried Types:** design\_rule\_check\_airwires, design\_rule\_check\_floating\_copper - **Manufacturing Review Offenders:** R6 - **Buck Output Target Voltage:** 5\.2V - **ERC/DRC Status:** Clean - **FloatingCopperIslands:** \[\] - **Part Type:** Portal - **Board Size:** 65\.0 mm x 30\.0 mm - **Manufacturing Quantity Target:** 10 - **ERC/DRC Report:** ERC/DRC checks run for: design\_rule\_check\_airwires, design\_rule\_check\_floating\_copper\. No remaining warnings\. - **Net: VIN – Net Type:** Power - **Feedback Low Resistor \(R7\) Value:** 10000Ω - **License:** http://solderpad\.org/licenses/SHL\-2\.1/ - **Copies:** 1 ## Key Components ### D1 — [SMF6\.0A](https://flux.ai/lcsc/smf6p0a~trkd.md) - Manufacturer Name: Liown\(里阳半导体\) - JLCPCB Part Class: Extended Part - Manufacturer Part Number: SMF6\.0A - Part Type: TVS - Role: Protection - LCSC Part Number: C2990428 - Package or Case Code: SOD\-123FL\_L2\.8\-W1\.9\-LS3\.7\-RD - Role Details: Transient suppression on Pi 5V rail \(PI\_5V to GND\) **Pins:** - 1 [pin 1] - 2 [pin 2] ### D2 — [MBRS540T3G](https://flux.ai/adrian95/mbrs540t3g~6kd.md) - Datasheet URL: https://www\.onsemi\.com/pdf/datasheet/mbrs540t3\-d\.pdf - Part Type: Diode - License: https://creativecommons\.org/licenses/by/4\.0/ - Manufacturer Name: onsemi - Manufacturer Part Number: MBRS540T3G **Pins:** - A [pin 2] - K [pin 1] ### D3 — [MBRS540T3G](https://flux.ai/adrian95/mbrs540t3g~6kd.md) - Datasheet URL: https://www\.onsemi\.com/pdf/datasheet/mbrs540t3\-d\.pdf - Part Type: Diode - License: https://creativecommons\.org/licenses/by/4\.0/ - Manufacturer Name: onsemi - Manufacturer Part Number: MBRS540T3G **Pins:** - A [pin 2] - K [pin 1] ### D5 — [6V Unidirectional TVS Diode](https://flux.ai/corynrobinson/6v-unidirectional-tvs-diode~4n.md) - Role: Protection - Datasheet URL: https://www\.littelfuse\.com/\~/media/electronics/datasheets/tvs\_diodes/littelfuse\_tvs\_diode\_smaj\_datasheet\.pdf\.pdf - Package: SMA - Manufacturer Part Number: SMAJ6\.0A - Role Details: TVS diode for transient suppression on VIN - Part Type: Diode - Package or Case Code: D\_SMA - Breakdown Voltage: 6V - Manufacturer Name: Littlefuse **Pins:** - A - K ### F2 — [ASMD1206\-200](https://flux.ai/lcsc/asmd1206-200~7b06.md) - Role Details: Series PTC fuse between BUCK\_5V and H1 pins 2/4 - Datasheet URL: https://storage\.googleapis\.com/graviton\-electric\-symbols/document\_assets/lcsc/2305151203\_Shenzhen\-JDT\-Fuse\-ASMD1206\-200\_C135342\.pdf - Product Info Url: https://lcsc\.com/product\-detail/Surface\-Mount\-Fuses\_2A\-Self\-recovery\_C135342\.html - LCSC Part Number: C135342 - JLCPCB Part Class: Extended Part - Holding Current: 1\.85A - Mount: Surface Mount - Part Type: Protection - Role: Protection - Manufacturer Name: JDTfuse\(集电通\) - Current Rating: 1\.85AA - Package or Case Code: F1206 - Manufacturer Part Number: ASMD1206\-200 **Pins:** - 1 [pin 1] - 2 [pin 2] ### H1 — [PPPC202LFBN\-RC](https://flux.ai/adrian95/pppc202lfbn-rc~nq3.md) - Manufacturer Name: ZHOURI - Manufacturer Part Number: 2\.54\-2\*20 - Datasheet URL: https://jlcpcb\.com/api/file/downloadByFileSystemAccessId/8589835176332734464 - Part Type: Connector - License: https://creativecommons\.org/licenses/by/4\.0/ **Pins:** - Pin\_1 [pin 1] - Pin\_10 [pin 10] - Pin\_11 [pin 11] - Pin\_12 [pin 12] - Pin\_13 [pin 13] - Pin\_14 [pin 14] - Pin\_15 [pin 15] - Pin\_16 [pin 16] - Pin\_17 [pin 17] - Pin\_18 [pin 18] - Pin\_19 [pin 19] - Pin\_2 [pin 2] - Pin\_20 [pin 20] - Pin\_21 [pin 21] - Pin\_22 [pin 22] - Pin\_23 [pin 23] - Pin\_24 [pin 24] - Pin\_25 [pin 25] - Pin\_26 [pin 26] - Pin\_27 [pin 27] - Pin\_28 [pin 28] - Pin\_29 [pin 29] - Pin\_3 [pin 3] - Pin\_30 [pin 30] - Pin\_31 [pin 31] - Pin\_32 [pin 32] - Pin\_33 [pin 33] - Pin\_34 [pin 34] - Pin\_35 [pin 35] - Pin\_36 [pin 36] - Pin\_37 [pin 37] - Pin\_38 [pin 38] - Pin\_39 [pin 39] - Pin\_4 [pin 4] - Pin\_40 [pin 40] - Pin\_5 [pin 5] - Pin\_6 [pin 6] - Pin\_7 [pin 7] - Pin\_8 [pin 8] - Pin\_9 [pin 9] ### J1 — [S2B\-PH\-K\-S\(LF\)\(SN\)](https://flux.ai/adrian95/s2b-ph-k-slfsn~brb.md) - Datasheet URL: https://www\.jst\-mfg\.com/product/pdf/eng/ePH\.pdf - Manufacturer Part Number: S2B\-PH\-K\-S\(LF\)\(SN\) - Manufacturer Name: JST Sales America Inc\. - Part Type: Connector - License: https://creativecommons\.org/licenses/by/4\.0/ **Pins:** - P1 [pin 1] - P2 [pin 2] ### J2 — [S2B\-PH\-K\-S\(LF\)\(SN\)](https://flux.ai/adrian95/s2b-ph-k-slfsn~brb.md) - Datasheet URL: https://www\.jst\-mfg\.com/product/pdf/eng/ePH\.pdf - Manufacturer Part Number: S2B\-PH\-K\-S\(LF\)\(SN\) - Manufacturer Name: JST Sales America Inc\. - Part Type: Connector - License: https://creativecommons\.org/licenses/by/4\.0/ **Pins:** - P1 [pin 1] - P2 [pin 2] ### J5 — [S2B\-XH\-A\(LF\)\(SN\)](https://flux.ai/jecstronic/s2b-xh-alfsn~mfn.md) - Part Type: Connector - License: https://creativecommons\.org/licenses/by/4\.0/ - Manufacturer Part Number: S2B\-XH\-A\(LF\)\(SN\) - Role Details: LED module connector: GPIO24 and GND only\. Use only with LED modules that include current limiting; bare LEDs require series resistors or a transistor/MOSFET driver\. - Datasheet URL: https://www\.jst\-mfg\.com/product/pdf/eng/eXH\.pdf - Manufacturer Name: JST **Pins:** - Pin\_1 [pin 1] - Pin\_2 [pin 2] ### J6 — [54\-00167](https://flux.ai/adrian95/54-00167~hqj.md) - Manufacturer Part Number: 54\-00166 - Part Type: Connector - Datasheet URL: http://tensility\.com/pdffiles/54\-00167\.pdf - Role Details: Tensility 54\-00166 barrel jack: A = VIN\_6V, B = GND, C = NC unless later used for plug detect/switch\. - Manufacturer Name: Tensility International Corp - License: https://creativecommons\.org/licenses/by/4\.0/ **Pins:** - A [pin 1] - B [pin 2] - C [pin 3] ### J7 — [S2B\-XH\-A\(LF\)\(SN\)](https://flux.ai/jecstronic/s2b-xh-alfsn~mfn.md) - Part Type: Connector - License: https://creativecommons\.org/licenses/by/4\.0/ - Manufacturer Part Number: S2B\-XH\-A\(LF\)\(SN\) - Role Details: LED module connector: GPIO25 and GND only\. Use only with LED modules that include current limiting; bare LEDs require series resistors or a transistor/MOSFET driver\. - Datasheet URL: https://www\.jst\-mfg\.com/product/pdf/eng/eXH\.pdf - Manufacturer Name: JST **Pins:** - Pin\_1 [pin 1] - Pin\_2 [pin 2] ### Q1 — [AO3400A\-HUASHUO](https://flux.ai/adrian95/ao3400a-huashuo~sl.md) - Datasheet URL: https://www\.lcsc\.com/datasheet/C700953\.pdf - Manufacturer Part Number: AO3400A - Drain to Source Voltage: 30V - Manufacturer Name: HUASHUO - Role Details: Motor driver low\-side MOSFET - Role: Switch - License: https://creativecommons\.org/licenses/by/4\.0/ - Part Type: Transistor **Pins:** - D [pin 3] - G [pin 1] - S [pin 2] ### Q2 — [AO3400A\-HUASHUO](https://flux.ai/adrian95/ao3400a-huashuo~sl.md) - Datasheet URL: https://www\.lcsc\.com/datasheet/C700953\.pdf - Manufacturer Part Number: AO3400A - Role Details: Motor driver low\-side MOSFET - Manufacturer Name: HUASHUO - Drain to Source Voltage: 30V - Role: Switch - License: https://creativecommons\.org/licenses/by/4\.0/ - Part Type: Transistor **Pins:** - D [pin 3] - G [pin 1] - S [pin 2] ### U1 — [TPS259531DSGT](https://flux.ai/lcsc/tps259531dsgt~rbhr.md) - Manufacturer Name: TI\(德州仪器\) - Role: Protection - LCSC Part Number: C1848342 - Package or Case Code: WSON\-8\_L2\.0\-W2\.0\-P0\.50\-TL\-EP - Role Details: Input eFuse for Pi 5V rail rated 3 A - Manufacturer Part Number: TPS259531DSGT - JLCPCB Part Class: Extended Part - Package: WSON\-8\_L2\.0\-W2\.0\-P0\.50\-TL\-EP **Pins:** - \~\{FLT\} [pin 6] - dVdt [pin 1] - EN/UVLO [pin 2] - EP [pin 9] - GND [pin 8] - ILM [pin 7] - IN [pin 3] - IN [pin 4] - OUT [pin 5] ### U2 — [TPS56339DDCR](https://flux.ai/lcsc/tps56339ddcr~jmlu.md) - Package or Case Code: TSOT\-23\-6\_L2\.9\-W1\.6\-P0\.95\-LS2\.8\-BR - Manufacturer Name: TI\(德州仪器\) - Manufacturer Part Number: TPS56339DDCR - Part Type: DC\-DC Converters - LCSC Part Number: C2071106 - JLCPCB Part Class: Extended Part **Pins:** - BOOT [pin 6] - EN [pin 5] - FB [pin 4] - GND [pin 1] - SW [pin 2] - VIN [pin 3] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://flux\.ai/bubbaa/stuck\-cyan\-lightcycle\-92e7\~yo](https://flux.ai/bubbaa/stuck-cyan-lightcycle-92e7~yo).* --- *Generated from [https://flux\.ai/bubbaa/stuck\-cyan\-lightcycle\-92e7\~yo](https://flux.ai/bubbaa/stuck-cyan-lightcycle-92e7~yo)*