The invention provides a high-precision over-temperature protection circuit. The high-precision over-temperature protection circuit is characterized by comprising a PTAT
reference current generation circuit, an over-temperature comparison
voltage generation circuit, a reference
voltage generation circuit and an over-temperature
comparator, the over-temperature comparison
voltage generation circuit and the PTAT
reference current generation circuit serve as
current mirror images of each other, the output end of the over-temperature comparison voltage generation circuit and the output end of the reference voltage generation circuit are connected with the
negative phase input end and the positive phase input end of the over-temperature
comparator respectively, and the output end of the over-temperature
comparator serves as output of the over-temperature protection circuit. Whether temperature exceeds the over-temperature protection threshold value is judged by comparing the over-temperature comparison voltage and the constant reference voltage, so that when the product temperature is too high, an over-temperature protection
signal is output, and a product is controlled to enter the temperature protection state. The circuit is simple in structure, the over-temperature protection trigger point is not influenced by the manufacturing process, and the high-precision over-temperature protection circuit is accurate, high in batch consistency and high in accuracy, can be used as an over-temperature protection module in products such as
integrated circuit chips, MCU modules and switch power supplies, and has good
market development value.