SCLS795A February 2020 – June 2020 SN74HCS4075
PRODUCTION DATA.
The SN74HCS4075 includes three 3-input OR gates with Schmitt-trigger inputs. These 3-input OR gates work independently, but can be combined to get up to a 7-input OR gate. It can be used with all three inputs active, or one input can be disabled by directly connecting it to ground to turn the device into a 2-input OR gate.
The SN74HCS4075 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 3-input OR gate function combines the three individual overheat signals into a single active-high enable signal.
Temperature sensors can often be spread throughout a system rather than being in a centralized location. This would mean longer length traces or wires to pass signals through leading to slower edge transitions. This makes the SN74HCS4075 ideal for the application since it has Schmitt-trigger inputs that do not have input transition rate requirements.