Snubbers are suppression circuits which are placed across IGBTs and switching transistors in power conversion circuits to suppress voltage transients and protect semiconductor devices from overvoltage. This paper shows how to design resistor-capacitor (RC) damping snubbers and the resistor-capacitor-diode (RCD) turn-off snubbers.
With so many types of capacitors available, circuit designers are faced with the challenge of selecting a capacitor that will be suitable for a specific snubber application. It is essential that the designer know the approximate conditions to which the capacitors will be exposed. The most important being peak voltage, temperature, dV/dt, and frequency. The designer may also be faced with constraints such as size, maximum allowable inductance, and cost. Once these conditions and constraints are identified the designer can begin the selection process.