USB-C Power Input & 3.3 V Regulator Board
Revision Status
| Revision | Status | Changes |
|---|---|---|
Rev A |
Active | (Initial release) |
The USB-C Power Input & 3.3 V Regulator Board is a simple building block board that combines USB-C power handling with a local 3.3 V regulated rail. It is designed to provide a stable, protected power foundation for bench prototypes and microcontroller projects.
Rather than designing a custom power stage for every prototype, this board serves as a reusable power supply block.
Features
- Dual Voltage Output: Provides both 5 V (VBUS) and regulated 3.3 V rails.
- Compact Footprint: Measures only 35 mm × 22 mm.
- 4-Layer Stack-up: Solid ground plane (layer 2) and power distribution routing (layer 3) for clean referencing and reduced noise.
- Production-Ready Parts: Uses standard 0805 and 0603 component footprints, which are small enough for automated assembly but still manageable for manual bench rework if needed.
- LED Control: A solder jumper is included to disconnect the power indicator LED to minimize power budgets for low-power testing.
- Mounting: Dual M2 mounting holes for temporary bench or enclosure installation.
Circuit & Component Details
- Linear Regulator: Based on the AP2114D-3.3 (LDO) linear regulator, providing a stable 3.3 V output.
- CC Pull-downs: 2 × 5.1 kΩ (0603) resistors connected to CC1 and CC2, ensuring that a USB-C source recognizes the board as a sink device and supplies 5 V.
- Input Protection:
- A 500 mA hold / 1 A trip PPTC resettable fuse on VBUS.
- An SMAJ5.0A TVS diode on VBUS to clamp input voltage transients.
- An MBR130LSFT1G Schottky diode to prevent voltage from being back-fed into the USB VBUS line.
- Data Line Protection: A USBLC6-2SC6 ESD protection array protects the USB high-speed D+ and D− lines.
Interface & Pinout
The board breaks out power and USB signal lines to a standard 2.54 mm pitch header:
| Pin | Label | Description |
|---|---|---|
| 1 | 5V | Unregulated 5 V from VBUS (downstream of fuse/Schottky) |
| 2 | 3.3V | Regulated 3.3 V output from AP2114 |
| 3 | GND | Common ground |
| 4 | D- | USB Data Negative (from USB-C port, via ESD protection) |
| 5 | D+ | USB Data Positive (from USB-C port, via ESD protection) |
Bill of Materials (BOM)
| Reference | Qty | Value | Footprint | LCSC Part No | MFR Part No | Description |
|---|---|---|---|---|---|---|
| J2 | 1 | Conn_01x05_Pin | Connector_PinHeader_2.54mm:PinHeader_1x05_P2.54mm_Vertical | C3337223 | HTSW-105-07-G-S | Pin Header 1 2.54mm 5.84mm 5P -55°C to +125°C 2.54mm 2.54mm 1x5P Through Hole, P=2.54mm Headers, Male Pins RoHS |
| J1 | 1 | 2171790001 | 2171790001:MOLEX_2171790001 | C3197684 | 2171790001 | USB Connectors Top-Mnt SMT 16Ckt Type C Rec. |
| C4 | 1 | 100nF | Capacitor_SMD:C_0805_2012Metric | C1845706 | C0805C104K4RACAUTO | Ceramic Capacitor, Multilayer, Ceramic, 16V, 10% +Tol, 10% -Tol, X7R, 15% TC, 0.1uF, Surface Mount, 0805 |
| D5 | 1 | SML-D12M8WT86 | LED_SMD:LED_0603_1608Metric_Pad1.05x0.95mm_HandSolder | C510025 | SML-D12M8WT86 | Single Colour LEDs SMD Yellow/Green 10-63 mcd |
| U2 | 1 | AP2114D-3.3TRG1 | Package_TO_SOT_SMD:TO-252-3_TabPin2 | C460311 | AP2114D-3.3TRG1 | - |
| D4 | 1 | MBR130LSFT1G | Diode_SMD:D_SOD-123 | C235756 | MBR130LSFT1G | Schottky Diodes & Rectifiers 1A 30V |
| F1 | 1 | 1206L050/15YR | Fuse:Fuse_1206_3216Metric_Pad1.42x1.75mm_HandSolder | C151162 | 1206L050/15YR | Polymeric PTC Resettable Fuse 15V 500mA Surface Mount 1206 |
| C1,C2,C3 | 3 | 10uF | Capacitor_SMD:C_0805_2012Metric | C95841 | CL21B106KOQNNNE | 10uF ±10% 16V Ceramic Capacitor X7R 0805 |
| D1 | 1 | SMAJ5.0A | Diode_SMD:D_SMA | C83329 | SMAJ5.0A | 9.2VC Clamp 43.5A Ipp TVS DIODE DO-214AC(SMA) |
| R1,R2 | 2 | 5.1K | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | C23162 | 0603WAF5101T5E | Thick Film Resistors - SMD RMC 0603 1/10W 1% T/R-5000 |
| R3 | 1 | 470R | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | C23179 | 0603WAF4700T5E | 470Ω ±1% 100mW 0603 Thick Film Resistor |
| U1 | 1 | USBLC6-2SC6 | Package_TO_SOT_SMD:SOT-23-6 | C7519 | USBLC6-2SC6 | 17VC Clamp 5A Ipp ESD DIODE SOT-23-6L |