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PCB Symbols Explained: 60 Common Labels You Should Know
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Ultimate PCB Component Reference: 60 Common Labels and Meanings
Understanding the abbreviations and labels on a PCB is essential for anyone working with electronics, from hobbyists to professional engineers. Here’s a complete guide to 60 common PCB labels, organized for clarity.
| Label | Meaning / Component | Notes |
|---|---|---|
| A | Amplifier | General amplifier circuit |
| B | Battery / Misc. | Sometimes used for specific components |
| C1, C2… | Capacitors | Differentiates multiple capacitors |
| D | Diode | Standard diode component |
| E | Electrolytic Capacitor | Occasionally used for electrolytics |
| F | Fuse | Protects circuits from overcurrent |
| IC | Integrated Circuit | Microchips on the board |
| J | Connector | General connectors for wiring |
| L | Inductor | Coil or inductor component |
| LED | Light Emitting Diode | Indicator or lighting element |
| M | Motor / Microcontroller | Varies by design |
| N | Negative Supply | Often denotes negative voltage |
| O | Optocoupler | Isolates circuits electrically |
| P | Plug / Socket | Electrical plug or socket |
| Q | Transistor | Switching or amplification |
| R1, R2… | Resistors | Distinguishes multiple resistors |
| S | Sensor | Any type of sensor |
| SW | Switch | General switch component |
| T | Transformer | Power or signal transformers |
| U | Integrated Circuit / Other | Can vary depending on the PCB |
| VR | Variable Resistor | Potentiometer or adjustable resistor |
| X | Crystal Oscillator | Frequency control component |
| Z | Custom / Special Component | Special use or manufacturer-specific |
| BAT | Battery | Power source |
| GND | Ground | Reference voltage point |
| VCC | Supply Voltage | Positive supply line |
| H | Hall Effect Sensor | Magnetic field detection |
| I | Input | Signal input line |
| K | Relay | Electromechanical switch |
| P1, P2… | Plugs / Sockets | Multiple connectors distinguished |
| S1, S2… | Switches | Multiple switches distinguished |
| T1, T2… | Transformers / Transistors | Different components distinguished |
| U1, U2… | Integrated Circuits | Unique IC identification |
| V | Voltage Regulator | Regulates circuit voltage |
| W | Wattmeter / Misc. | Can indicate other power-related components |
| X1, X2… | Crystal Oscillators | Multiple crystals differentiated |
| Y | Custom Component | Special or proprietary part |
| Z1, Z2… | Impedance / Special | Used for custom or special networks |
| ADC | Analog-to-Digital Converter | Converts analog signals to digital |
| DAC | Digital-to-Analog Converter | Converts digital signals to analog |
| MCU | Microcontroller Unit | Embedded processing unit |
| DSP | Digital Signal Processor | Signal processing component |
| FPGA | Field Programmable Gate Array | Reconfigurable digital logic |
| LDO | Low Dropout Regulator | Voltage regulation |
| OPAMP | Operational Amplifier | Amplification and signal processing |
| PWM | Pulse Width Modulator | Controls duty cycle of signals |
| RS232 | Serial Interface | Standard serial communication |
| USB | Universal Serial Bus | Digital connectivity |
| SD | Secure Digital Card Interface | Memory card interface |
| HDMI | High Definition Multimedia Interface | Audio-video interface |
| Ethernet | Network Connection | Wired LAN connection |
| Wi-Fi | Wireless LAN | Wireless network interface |
| Bluetooth | Wireless Communication | Short-range wireless interface |
| NFC | Near Field Communication | Close-range wireless interface |
| GPIO | General Purpose I/O | Input/output pins for control |
| SPI | Serial Peripheral Interface | Serial communication bus |
| I2C | Inter-Integrated Circuit | Two-wire serial bus |
| UART | Universal Asynchronous Receiver/Transmitter | Serial communication protocol |
| CAN | Controller Area Network | Automotive/industrial interface |
| JTAG | Test & Debug Interface | Debugging and testing connections |
Why This Guide Matters
- Quick Reference: Perfect for PCB assembly, repair, and troubleshooting.
- Efficiency Boost: Reduces errors and speeds up identifying components.
- For Engineers & Hobbyists: Improves understanding of PCB design and labeling conventions.
