# Handicapped Salmon Lightcycle
## Description
USB-C to SATA portable external hard drive enclosure controller. Architecture includes USB Type-C 5 V sink input with 5.1 kΩ CC pull-downs, VBUS ESD/TVS and overcurrent protection, USB 3.2 Gen1 SuperSpeed differential pairs into a USB-to-SATA bridge, SATA data and power output for a 2.5-inch drive, regulated 3.3 V logic rail with optional 1.8 V rail if required by the bridge, 25 MHz reference clock, power/activity LEDs, and test points. Design target is compact portable use with stable spin-up power delivery, low EMI, controlled-impedance high-speed routing, and production-grade BOM options.
## Project Details
- **Owner:** jefferry
- **Created:** 3/19/2026
- **Last Updated:** 3/19/2026
- **Visibility:** Public
- **System Architecture:** ```mermaid
flowchart TD
USBC["USB-C Receptacle"] --> PROT["VBUS Protection and OCP"]
PROT --> SYS5["Protected 5V Rail"]
SYS5 --> REG33["3.3V Regulator"]
REG33 --> BRIDGE["USB to SATA Bridge"]
REG33 --> AUX18["Optional 1.8V Regulator"]
AUX18 --> BRIDGE
USBC --> USBHS["USB 3.x SuperSpeed Pairs"]
USBHS --> BRIDGE
BRIDGE --> SATA["SATA Data and Power Connector"]
XTAL["25MHz Crystal"] --> BRIDGE
LEDS["Power and Activity LEDs"] --> BRIDGE
TPS["Debug Test Points"] --> SYS5
TPS --> REG33
TPS --> AUX18
TPS --> SATA
```
## Key Components
### D1 — [SML-D13FWT86C](https://www.flux.ai/jecstronic/sml-d13fwt86c.md)
- Role Details: Green power LED indicating 3.3V rail present
- Datasheet URL: https://fscdn.rohm.com/en/products/databook/datasheet/opto/led/chip_mono/sml-d13fwt86(c)-e.pdf
- Role: Indicator
- Package: 0603
- Manufacturer Name: Rohm Semiconductor
- Manufacturer Part Number: SML-D13FWT86C
- License: https://creativecommons.org/licenses/by/4.0/
- Part Type: LED
**Pins:**
- A [pin 2]
- K [pin 1]
### D2 — [SML-D13FWT86C](https://www.flux.ai/jecstronic/sml-d13fwt86c.md)
- Role Details: Green activity LED driven by bridge status output
- Datasheet URL: https://fscdn.rohm.com/en/products/databook/datasheet/opto/led/chip_mono/sml-d13fwt86(c)-e.pdf
- Manufacturer Part Number: SML-D13FWT86C
- Package: 0603
- Manufacturer Name: Rohm Semiconductor
- Part Type: LED
- License: https://creativecommons.org/licenses/by/4.0/
- Role: Indicator
**Pins:**
- A [pin 2]
- K [pin 1]
### J1 — [TYPE-C-31-M-12](https://www.flux.ai/vasy_skral/type-c-31-m-12.md)
- Manufacturer Part Number: TYPE-C-31-M-12
- Datasheet URL: https://en.krhro.com/npublic/opdfjs/web/viewer.html?file=https%3A%2F%2Fomo-oss-file.thefastfile.com%2Fportal-saas%2Fnew2023011311465142457%2Fcms%2Ffile%2F95f41c83-14fa-41cb-9f86-8d6a717317e5.pdf
- Part Type: Connector
- License: https://creativecommons.org/licenses/by/4.0/
- Role: Connector
- Manufacturer Name: Korean Hroparts Elec
- Role Details: USB-C input connector for USB 3.x sink device
- Symbol Style: Parametric
- Package: USB-C Receptacle
**Pins:**
- CC1 [pin A5]
- CC2 [pin B5]
- DN1 [pin A7]
- DN2 [pin B7]
- DP1 [pin A6]
- DP2 [pin B6]
- GND [pin B1A12]
- GND [pin A1B12]
- SBU1 [pin A8]
- SBU2 [pin B8]
- SHIELD [pin S3]
- SHIELD [pin S1]
- SHIELD [pin S4]
- SHIELD [pin S2]
- VBUS [pin B4A9]
- VBUS [pin A4B9]
### J2 — [1735944-1](https://www.flux.ai/adrian95/1735944-1.md)
- Role: Connector
- Role Details: Combined SATA data and power connector for 2.5-inch HDD or SSD
- Package or Case Code: 17359441
- License: https://creativecommons.org/licenses/by/4.0/
- Datasheet URL: https://www.te.com/commerce/DocumentDelivery/DDEController?Action=srchrtrv&DocNm=1735944&DocType=Customer+Drawing&DocLang=English
- Manufacturer Name: TE Connectivity
- Package: SATA 22-pin SMT
- Part Type: Connector
- Manufacturer Part Number: 1735944-1
**Pins:**
- MP1 [pin MP1]
- MP2 [pin MP2]
- P1 [pin P1]
- P10 [pin P10]
- P11 [pin P11]
- P12 [pin P12]
- P13 [pin P13]
- P14 [pin P14]
- P15 [pin P15]
- P2 [pin P2]
- P3 [pin P3]
- P4 [pin P4]
- P5 [pin P5]
- P6 [pin P6]
- P7 [pin P7]
- P8 [pin P8]
- P9 [pin P9]
- S1 [pin S1]
- S2 [pin S2]
- S3 [pin S3]
- S4 [pin S4]
- S5 [pin S5]
- S6 [pin S6]
- S7 [pin S7]
### U2 — [TPS259531DSGT](https://www.flux.ai/lcsc/tps259531dsgt.md)
- Role Details: USB VBUS e-fuse and inrush/current limiting for protected 5V rail
- Manufacturer Name: TI(德州仪器)
- Package: WSON-8
- Package or Case Code: WSON-8_L2.0-W2.0-P0.50-TL-EP
- Manufacturer Part Number: TPS259531DSGT
- JLCPCB Part Class: Extended Part
- Role: Input Protection
- LCSC Part Number: C1848342
**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]
### U3 — [TPD4EUSB30DQAR](https://www.flux.ai/vasy_skral/tpd4eusb30dqar.md)
- Manufacturer Name: Texas Instruments
- Part Type: Protection
- Manufacturer Part Number: TPD4EUSB30DQAR
- Role Details: Low-capacitance protection for USB 3.x SuperSpeed differential pairs
- Package: USON-10
- Role: ESD Protection
- Datasheet URL: https://www.ti.com/general/docs/suppproductinfo.tsp?distId=10&gotoUrl=https%3A%2F%2Fwww.ti.com%2Flit%2Fgpn%2Ftpd4eusb30
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- D1- [pin 2]
- D1+ [pin 1]
- D2- [pin 5]
- D2+ [pin 4]
- GND [pin 8]
- GND [pin 3]
- NC [pin 10]
- NC [pin 6]
- NC [pin 7]
- NC [pin 9]
### U4 — [AP2112K-3.3TRG1](https://www.flux.ai/adrian95/ap2112k-33trg1.md)
- Datasheet URL: Diodes Incorporated
- Manufacturer Name: https://www.diodes.com/assets/Datasheets/AP2112.pdf
- Package: SOT-25
- Role Details: Main 3.3V rail derived from protected USB 5V input
- Part Type: Integrated Circuit
- Manufacturer Part Number: AP2112K-3.3TRG1
- Role: Regulator
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- EN [pin 3]
- GND [pin 2]
- NC [pin 4]
- VIN [pin 1]
- VOUT [pin 5]
### U5 — [AP2112K-1.8TRG1](https://www.flux.ai/adrian95/ap2112k-18trg1.md)
- Manufacturer Name: Diodes Incorporated
- License: https://creativecommons.org/licenses/by/4.0/
- Datasheet URL: https://www.diodes.com/assets/Datasheets/AP2112.pdf
- Role: Regulator
- Manufacturer Part Number: AP2112K-1.8TRG1
- Part Type: Integrated Circuit
- Package: SOT-25
- Role Details: Optional 1.8V auxiliary rail for bridge core or PHY supply variants
**Pins:**
- EN [pin 3]
- GND [pin 2]
- NC [pin 4]
- VIN [pin 1]
- VOUT [pin 5]
### Y1 — [NX3225GA-25MHZ-STD-CRG-2](https://www.flux.ai/lcsc/nx3225ga-25mhz-std-crg-2.md)
- Role: Timing
- Package: 3225
- Manufacturer Part Number: NX3225GA-25MHZ-STD-CRG-2
- Part Type: Crystals
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_NDK-NX3225GA-25MHZ-STD-CRG-2_C438901.pdf
- Package or Case Code: OSC-SMD_4P-L3.2-W2.5-BL
- Product Info Url: https://lcsc.com/product-detail/SMD-Crystal-Resonators_NDK-NX3225GA-STD-CRG-2-25MHZ_C438901.html
- Role Details: 25MHz reference clock for USB-to-SATA bridge
- JLCPCB Part Class: Extended Part
- LCSC Part Number: C438901
- Manufacturer Name: NDK
**Pins:**
- 1 [pin 1]
- 3 [pin 3]
- GND [pin 4]
- GND [pin 2]
*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/jefferry/handicapped-salmon-lightcycle](https://www.flux.ai/jefferry/handicapped-salmon-lightcycle).*
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