Home▸Physics & Mechanics▸Linear Voltage Regulator (LDO) Explained

⚡ Linear Voltage Regulator (LDO) Explained

Interactive 3D LDO regulator circuit where varying input voltage and load current shows output voltage regulation, dropout voltage and power dissipation responding live.

Physics & Mechanics3DModerate60 FPS

A 3D pass-transistor circuit shows how an LDO regulator holds a steady output voltage by absorbing excess input voltage as heat, and what happens when the input gets too close to the setpoint.

🔬 What It Demonstrates

The glowing iris valve represents the pass transistor's effective resistance, opening as the input-to-output voltage gap shrinks. Once the gap drops below the dropout spec, regulation is lost and the output starts tracking the input directly.

🎮 How to Use

Sweep input voltage and load current to watch the output voltage, dropout margin, dissipated power and junction temperature respond live. Change the output setpoint and dropout spec to compare regulator designs.

💡 Did You Know?

All of the voltage an LDO "regulates away" becomes heat: P = (V_IN − V_OUT) × I_LOAD. That's why linear regulators are simple and quiet but far less efficient than switching converters for large voltage drops.

⚙ Under the hood

Interactive 3D LDO regulator circuit where varying input voltage and load current shows output voltage regulation, dropout voltage and power dissipation responding live.

ldo-regulatorvoltage-regulationpower-electronicsdropout-voltagecircuitsphysics

3D · Three.js / WebGL renderer · 60 FPS target · runs fully client-side, no install