FASTON 250 PCB Power Terminal
Heavy-duty FASTON 250 series PCB tab terminal for busboard power connection, supporting thick gauge wire for low-noise power delivery to Eurorack modules.
Overview
The FASTON 250 terminal (1217754-1) is an industrial-grade quick-connect PCB tab terminal from TE Connectivity. It provides a robust power output interface for connecting the USB-PD power supply to a Eurorack busboard using standard FASTON 250 (6.35mm / 0.250") receptacle connectors.
This design uses 4 terminals for the three power rails plus ground return:
| Terminal | Signal | Purpose |
|---|---|---|
| J6 | -12V | Negative 12V output |
| J7 | +12V | Positive 12V output |
| J8 | +5V | Positive 5V output |
| J9 | GND | Common ground return |
Key Specifications
| Parameter | Value | Notes |
|---|---|---|
| JLCPCB Part Number | C305825 | This design |
| Manufacturer | TE Connectivity | |
| Manufacturer Part Number | 1217754-1 | FASTON 250 Series |
| Tab Width | 6.35mm (0.250") | Standard FASTON 250 size |
| Current Rating | 7A continuous | Per terminal |
| Voltage Rating | 250V | Far exceeds 15V requirement |
| Contact Material | Tin-plated brass | Low resistance, corrosion-resistant |
| Mounting Type | Through-hole (THT) | Wave soldering |
| PCB Thickness | 1.57-2.36mm | Standard PCB compatible |
| Assembly Fee | $0.03/piece | JLCPCB special component fee |
Why FASTON Terminals?
Advantages for Eurorack Power Distribution
-
Low-Noise Power Delivery
- Supports thick gauge wire (18-22 AWG typical)
- Lower resistance than thin ribbon cables
- Reduces voltage drop under load
-
High Current Capacity
- 7A per terminal far exceeds requirements
- +12V: 1.5A max (21% of capacity)
- Combined GND: ~4A max (57% of capacity)
-
Industrial Reliability
- TE Connectivity quality
- 10,000+ mating cycles typical
- Secure connection won't vibrate loose
-
Easy Busboard Connection
- Standard FASTON receptacles widely available
- Quick connect/disconnect without tools
- Same connectors used on commercial busboards
Application in This Project
Power Output Configuration
USB-PD Power Supply Busboard
┌─────────────────┐ ┌─────────────────┐
│ │ FASTON cable │ │
│ J6 [-12V] ─────┼───────────────────┼─→ -12V rail │
│ J7 [+12V] ─────┼───────────────────┼─→ +12V rail │
│ J8 [+5V] ─────┼───────────────────┼─→ +5V rail │
│ J9 [GND] ─────┼───────────────────┼─→ GND plane │
│ │ │ │
└─────────────────┘ └─────────────────┘
Current Flow Analysis
| Terminal | Signal | Max Design Current | Terminal Rating | Margin |
|---|---|---|---|---|
| J6 | -12V | 0.8A | 7A | 775% |
| J7 | +12V | 1.2A | 7A | 483% |
| J8 | +5V | 0.5A | 7A | 1300% |
| J9 | GND | 2.5A (combined) | 7A | 180% |
Note: GND terminal carries combined return current from all three rails. Even at maximum load, this is well within the 7A rating.
Single GND Terminal Rationale
In Eurorack systems, all GND pins from module power connectors are tied together on the busboard. Using a single GND return terminal is appropriate because:
- The busboard already combines all GND connections
- Maximum combined return current (~2.5A) is well within 7A rating
- Reduces terminal count and simplifies wiring
- Matches common Eurorack busboard designs
Mating Connectors
To connect to the FASTON tabs, use standard FASTON 250 receptacles:
| Type | Wire Size | Insulation | Typical Source |
|---|---|---|---|
| Crimp receptacle | 18-22 AWG | Fully insulated | Electronics distributors |
| Quick-disconnect | 18-22 AWG | Partially insulated | Hardware stores |
| Wire-to-board cable | Pre-made | Various | Custom cable assemblies |
Recommended: Use fully-insulated crimp receptacles with 18 AWG wire for lowest resistance and best current capacity.
PCB Layout Considerations
- Pad reinforcement: Through-hole mounting provides mechanical strength
- Trace width: Use wide traces (>1mm) for power connections to FASTON pads
- Placement: Position terminals at board edge for easy cable access
- Spacing: Maintain adequate clearance between terminals for insulated receptacles
Related Components
- J1 - USB Type-C Connector - Power input
- J2 - 2x8 Pin Header - Direct module connection
- Bill of Materials - Complete parts list