"24V DC Cooling Fan" fan stall, open or unconnected causes the TC642 to trigger a start the timer. If the fault persists, FAULT output goes low, and the device is locked in shutdown mode. When the PWM output duty cycle reaches 100%, FAULT output pin will output low, indicating a possible thermal runaway. The fan continues to run. For more information on the device and system design guidelines, see Section 5.0 "Typical applications". TC642 is available in a standard 8-pin plastic DIP, SOIC and MSOP packages, and commercial, extended commercial and industrial products.