TC620 and TC621 are programmable logic output temperature detectors designed for use in thermal management applications. The TC620 features an on-board temperature sensor， while the TC621 connects to an external NTC thermistor for remote sensing applications. Both devices feature dual thermal interrupt outputs （HIGH LIMIT and LOW LIMIT）， each of which program with a single external resistor. On the TC620， these outputs are driven active （high） when measured temperature equals the user-programmed limits. The CONTROL （hysteresis） output is driven high when temperature equals the high limit setting， and returns low when temperature falls below the low limit setting. This output can be used to provide simple ON/OFF control to a cooling fan or heater. The TC621 provides the same output functions except that the logical states are inverted. The TC620/621 are usable over a maximum temperature range of – 40C to +125C.