Design of a High Precision Thermal-Shutdown Circuit
Tan Yuli · Dianzi qijian · 2016
Based on UMC 0.25 μm BCD technology,a high precision thermal-shutdown circuit is proposed. Thetemperature detection is achieved by using the negative temperature characteristic of transistor's base-emitter volt-age of bandgap reference. The hysteresis temperature is produced by adjusting the ratio of resistance to avoid thephenomenon of thermal oscillation. By simulation and verification with HSPICE,the thermal-shutdown output re-verses to shut down the chip when the temperature reaches 130 ℃,and return to normal working when the tempera-ture drops to 99 ℃. The amount of hysteresis temperature is 31 ℃. The thermal shutdown threshold and hysteresistemperature have a maximum drift error of only 0.24 ℃ when supply voltage changes.