Voltage refers to the potential difference between two points, with GND defined as the 0V reference. A node potential lower than 0V is negative voltage. This does not require a special power supply; it simply means the potential is lower relative to the reference ground.
Key Technical Points
- GND is an artificially selected 0V reference point and can be defined arbitrarily.
- +5V means the node potential is 5V higher than ground, while -5V means the node potential is 5V lower than ground.
- AC signals swing both positively and negatively around 0V. A single-supply power rail cannot capture the complete waveform.
Conclusion
Most analog, communication and driver circuits rely on bidirectional potential ranges. Failure to understand the definition of negative voltage will cause operational amplifier clipping, faulty interface communication and abnormal device biasing. Mastering this concept is a fundamental prerequisite for power supply design.
Further Reading on Negative Voltage Fundamentals
- Negative Voltage Basics: What Is Negative Voltage?
- Negative Voltage Basics: Voltages in Communication Circuits
- Negative Voltage Basics: Why Op-Amp & Audio Analog Circuits Require Positive/Negative Power Supplies
- Negative Voltage Basics: Charge Pump Implementations
- Negative Voltage Basics: Positive and Negative Voltage Design for Buck Circuits
- Negative Voltage Basics: Negative Rail Supply for Precision Op-Amp AC Signal Amplification