In this application, three 2-input OR gates are combined to produce a 4-input OR gate function as shown in GUID-EC1AF40C-31F1-4E51-87A1-A7C3F9F34971.html#APP1_SCHEM. The fourth gate can be used for another application in the system, or the inputs can be grounded and the channel left unused.

This device is used to directly control the Enable pin of a fan driver. The fan driver requires only one input signal to be HIGH before being enabled, and should be disabled in the event that all signals go LOW. The 4-input OR gate function combines the four individual overheat signals into a single active-high enable signal.