To properly negotiate 5V power from a USB-C connection, you'll need two 5.1kΩ ±20% pull-down resistors connected to ground on both Configuration Channel (CC) pins
```mermaid flowchart LR subgraph "USB-C Power Negotiation" direction TB
subgraph "Configuration Channels"
CC1["CC1 Pin"] & CC2["CC2 Pin"]
end
subgraph "Resistors"
R1["5.1kΩ ±20%
Pull-down"] & R2["5.1kΩ ±20%
Pull-down"]
end
subgraph "Ground Connection"
GND(("GND"))
end
CC1 --> R1 --> GND
CC2 --> R2 --> GND
end
style CC1 fill:#f96,stroke:#333,color:#000
style CC2 fill:#f96,stroke:#333,color:#000
style R1 fill:#9cf,stroke:#333,color:#000
style R2 fill:#9cf,stroke:#333,color:#000
style GND fill:#9f9,stroke:#333,color:#000
```
thedeveloperguy.com . These resistors are essential for proper USB-C power negotiation and safety compliance. Why These Resistors Are Needed
They indicate to the USB-C source that your device is requesting power
They enable proper voltage negotiation
They ensure safe operation within USB-C specifications
They prevent potential damage to either device
Now would be the perfect time to add a Mermaid diagram showing the physical connections. I'll create a clear diagram showing: 1. Both CC pins 2. Ground connections 3. Resistor values 4. Clear directional flow Looking at the diagram, I should clarify a few points: 1. The physical orientation of CC pins isn't clear 2. Users might wonder why there are two identical paths 3. The purpose of having both channels should be explained
Let me add this information before moving on to the technical specifications.
Important notes about the connections shown above:
Both CC1 and CC2 must be connected this way because USB-C cables can be inserted either way
CC1 is typically located near pin A5, while CC2 is near pin B5
Both channels must have identical resistor configurations for proper operation
Technical Specifications
Resistor Value: 5.1kΩ ±20%
Type: Pull-down resistors
Connection: Both ends connect directly to ground
Maximum Input Capacitance: 10μF (recommended 4.7μF for safety margin)
thedeveloperguy.com
Important Safety Note While these resistors alone will enable basic power negotiation, always verify that your USB-C source can supply enough current for your device's requirements. The standard allows up to 3A at 5V, but not all USB-C ports support this maximum current.