USB-C Connector
Overview
This connector provides power delivery (with appropriate jumper position) and programming connectivity for an ESP32-S3 microcontroller. The design includes comprehensive protection, proper USB-C device configuration, and power source selection for both development and production environments.
Main Components
USB-C Connector (J19)
- Part Number: TYPE_C_31_M_12
- Configuration: USB 2.0 device mode
- Power Capability: 5V delivery via USB-C VBUS
- Data Support: Full-speed USB communication and programming
Power Management System
Power Source Selection (J17)
- Component: 2.54mm jumper header (2.54-1*2P)
- Function: Selects between USB power and external power isolation
- Jumper Installed: ESP32-S3 system powered by USB 5V
- Jumper Removed: Programming-only mode (no USB power delivery)
Battery Power Isolation
- Method: Manual jumper control of TPS4800-Q1 INP pin (Pin 3)
- Implementation: 2-pin header interrupts connection between VIN and INP
- USB Mode: Remove battery jumper → INP floating → TPS4800 disabled → battery path isolated
- Battery Mode: Install battery jumper → INP connected to VIN → normal battery operation
USB-C Configuration
Configuration Channel (CC) Setup
- CC1 Pin (A5): 5.1kΩ pull-down resistor to GND
- CC2 Pin (B5): 5.1kΩ pull-down resistor to GND
- Result: USB device mode advertisement to host
- Compliance: USB-C specification for sink device identification
Data Line Implementation
- USB D+ (A6/B6): Connected through 22Ω series resistor and ESD protection
- USB D- (A7/B7): Connected through 22Ω series resistor and ESD protection
- Destination: ESP32-S3 GPIO19 (D-) and GPIO20 (D+)
- Signal Integrity: 22Ω resistors provide impedance matching and current limiting
ESD Protection
- Component: Dual low-capacitance TVS diode array (e.g., USBLC6-2SC6)
- Placement: Between series resistors and ESP32-S3 data pins
- Specifications: <1pF capacitance, ~6V clamping voltage
- Protection: Guards against electrostatic discharge on exposed USB connector
ESP32-S3 Interface
USB Connection
- ESP32-S3 D+: GPIO20 (dedicated USB OTG pin)
- ESP32-S3 D-: GPIO19 (dedicated USB OTG pin)
- USB Protocol: Native USB OTG support in ESP32-S3
- Programming: CDC/ACM or vendor-specific protocol over USB
Power Connection
- 5V Rail: Delivered from USB VBUS when J17 jumper installed
- Regulation: 5V → 3.3V via TLV62569DBV buck converter (existing system)
- ESP32-S3 Power: 3.3V rail powers ESP32-S3 and peripherals
Pin Mapping Summary
| USB-C Pin |
Signal |
Series R |
ESD Protection |
ESP32-S3 Pin |
Function |
| A4/B4 |
VBUS |
- |
- |
- |
5V power via J17 |
| A5 |
CC1 |
- |
- |
- |
5.1kΩ to GND (device mode) |
| B5 |
CC2 |
- |
- |
- |
5.1kΩ to GND (device mode) |
| A6/B6 |
D+ |
22Ω |
TVS array |
GPIO20 |
USB data positive |
| A7/B7 |
D- |
22Ω |
TVS array |
GPIO19 |
USB data negative |
| A8/B8 |
SBU1/SBU2 |
- |
- |
- |
Not connected |
| Shield |
SHIELD |
- |
- |
- |
Chassis ground |
Power System Integration
Power Flow Architecture
- USB Mode: USB VBUS → J17 → 5V rail → 3.3V buck → ESP32-S3
- Battery Mode: Battery → TPS4800 → 5V buck → 3.3V buck → ESP32-S3
- Isolation: Never both sources simultaneously (prevented by jumper design)
Power Consumption (USB Mode)
| Component |
Current |
Rail |
Power |
| ESP32-S3 (active) |
80mA |
3.3V |
264mW |
| ESP32-S3 (sleep) |
10µA |
3.3V |
33µW |
| Support circuits |
~26mA |
Mixed |
~130mW |
| Total USB current |
~400mA |
5V |
~2W |
Power Source Selection Matrix
| Battery Jumper (INP) |
USB Jumper (J17) |
Result |
Battery Current |
USB Current |
| Installed |
Removed |
Battery only |
88µA + load |
0mA |
| Removed |
Installed |
USB only |
0µA |
~400mA |
| Removed |
Removed |
No power |
0µA |
0mA |
| Installed |
Installed |
⚠️ CONFLICT |
AVOID |
AVOID |
Programming and Operation
Programming Mode
- Connection: Standard USB-C cable to development host
- Protocol: Native USB programming via ESP32-S3 USB OTG
- Boot Mode: Manual - hold GPIO0 low during reset for programming
- Auto-reset: Not implemented (manual reset required)
- Power: Via USB (J17 installed) or external power (J17 removed)
Production Operation
- Power Source: Typically battery power (USB jumpers removed)
- USB Connector: Can remain populated for field programming
- ESD Protection: Protects ESP32-S3 from connector exposure
- Serviceability: Manual jumper control allows power source selection
Design Features
Protection Systems
- ESD Protection: TVS diodes on USB data lines USBLC6-2SC6
- Power Isolation: Jumper-controlled source selection
- Overcurrent: Inherent USB host current limiting
- Signal Integrity: Series termination resistors
Production Considerations
- Component Selection: Standard values for easy sourcing
- Manual Programming: Acceptable for production programming workflow
- Power Flexibility: Supports both development and deployment scenarios
- EMI Compliance: ESD protection aids regulatory compliance
User Interface
- J17 Power Jumper: Controls USB power delivery to system
- INP Control Jumper: Controls battery power path isolation
- Programming: Standard USB-C connector with manual boot control
- Status: Power source clearly defined by jumper positions
Operational Modes
Development Mode
- Install J17 jumper (USB power)
- Remove battery jumper (isolate battery)
- Connect USB-C cable
- Manual reset/GPIO0 control for programming
Production Mode
- Remove J17 jumper (no USB power)
- Install battery jumper (battery power)
- USB connector available for field programming if needed
Programming Mode (Either Power Source)
- Connect USB-C cable for data
- Set power jumpers as desired
- Hold GPIO0 low, press reset
- Release reset, then GPIO0
- Program via USB interface
This design provides a robust, production-ready USB-C interface with comprehensive protection and flexible power management for ESP32-S3 based systems.