Power Management—Redundant Fan System

The failure of a single fan can cause the temperature inside a high-density electronic system to rise rapidly in a short period of time. In high reliability and critical applications it is essential to detect fan failures and prevent consequential failure of the entire system by taking appropriate action. This Application Note details the actions that prevent system failure:

1. Increasing the speed of the other fans in the system to compensate for the loss of airflow due to the loss of the fan.

2. Signaling the host controller of fan failure.