SOLUTION

Snubber Circuit: A Protective Shield for Power Devices

• A snubber circuit is a protective circuit element commonly used in power electronic systems. Its primary function is to suppress the high-voltage transients (spikes) that can occur during the switching process of power devices like transistors, diodes, and thyristors.

Why is Suppressing dV/dt Important?

When a power device switches rapidly, it can induce high-voltage spikes due to parasitic inductances and capacitances in the circuit. These spikes can lead to:

• Device Damage: Excessive voltage stress can damage the device.
• Electromagnetic Interference (EMI): These spikes can generate electromagnetic interference, affecting other electronic devices.
• Switching Losses: High-voltage spikes can increase switching losses, reducing the efficiency of the power converter.

How a Snubber Circuit Works:

A typical snubber circuit consists of a resistor (R) and a capacitor (C) connected in parallel across the power device. When the device switches, the capacitor absorbs the excess energy, limiting the rate of voltage rise (dV/dt). The resistor dissipates the energy stored in the capacitor.

Slow down the rate of voltage change (dV/dt): By providing an alternative path for the current, the snubber limits the voltage across the switching device, reducing dV/dt.