一种低功耗CMOS过温保护电路的设计

摘要

Aiming at the shortcomings of the traditional over⁃temperature protection ( OTP ) circuit, for example, thermal threshold and hysteresis were seriously affected by power supply voltage and power consumption was large, based on the 0.18 μm BCD process, a new type of OTP circuit was designed with high stability and low power con⁃sumption. The temperature threshold and hysteresis were realized by introducing the feedback technique with tem⁃perature coefficient current. The simulation results of Hspice show that it can shut down the system accurately to protect the circuit when the temperature reaches 138℃ and the system recovers to normal work when the tempera⁃ture reduces to 126 ℃. The variation of thermal shutdown threshold and hysteresis were 1.75 ℃ and 0.05 ℃ re⁃spectively when supply voltage ranges from 3 to 5 V. The circuit was characterized by simple structure, low power consumption and strong anti⁃interference ability. The OTP circuit shows excellent performance, which satisfies the requirement of low power consumption and high stability in OTP circuit design.%针对传统过温保护（OTP）电路的温度阈值点和迟滞量受电源电压影响较大和功耗大等缺点，基于0．18μm BCD工艺，设计了一种新型的高稳定和低功耗的过温保护电路。通过引入带有温度系数电流的反馈技术实现温度阈值点和迟滞量。 Hspice仿真结果表明，当温度达到138℃时，能准确地关闭系统，达到保护电路的目的；当温度降低126℃时，系统恢复正常工作。电源电压在3～5 V之间变化时，过温保护的温度阈值点和迟滞漂移量分别为1．75℃和0．05℃，该电路具有结构简单、功耗低和抗干扰能力强等特点，过温保护电路表现出优良的性能，满足了过温保护电路的低功耗和高稳定性的设计要求。