A novel thermal sensor is designed and fabricated based on spin-transfer torque operated magnetic tunnel junction (STT-MTJ) device. It can fulfill thermal detection and overheat protection on integrated circuit. Moreover, it shows over 10 times faster thermal transit response speed than that of traditional CMOS thermal sensor. The unique property is really helpful for controlling integrated circuit's temperature due to heating by leakage current. A power driver at full loading situation is used to demonstrate this design. It shows that the sensor can be adopted as adaptive manner in a power source scaling strategy to cool down the IC in an effective way, showing a promising potential application not only as discrete sensor, but also as power solution for IC driver.