Hello mavern1,

By design, the resistor in a snubber circuit is a power dissipative element, so it must be thermally rated to handle the appropriate power. The CRD-CIL23N-GMA is used for clamped inductive load (CIL) tests which typically only requires two short pulses (~5-100us) followed by a long break between tests (>1s). Even if the resistor in its snubber must dissipate a high instantaneous power during the CIL switching events, it has significant cooling time such that it does not require a high continuous power rating.

In contrast, the CRD200DA23N-GMA design is intended to operate continuously, and thus must have a higher continuous power rating. This was accomplished by paralleling multiple resistors. Furthermore, there are multiple RC snubbers on the board to ensure that each power module has a closely routed snubber to ensure a low-inductance connection. Additionally, most end applications have well-defined operating conditions (i.e. switching frequency, load, etc.), whereas the CRD200DA23N-GMA design is intended to support a variety of customers in many applications and operating conditions. Because of this, we elected to add additional resistor power rating to ensure its sufficient in all applications. If you are trying to identify the appropriate resistor power requirements for your snubber, I recommend developing a LTspice model of your system using the model of the power module which is available for download here.

Thanks,

Chris N.