【摘要】 利用热等效电路对外加连续脉冲产生的热效应中晶格温度的上升及下降作了研究并与实验进行了比较.结果表明,若高频脉冲的延迟时间大于降温驰豫时间,则器件处于热安全工作区.对热阻为3.5K/W,热容为5μs.W/K的LDMOS,如脉冲频率小于7.14kHz且占空比为0.5,或脉冲频率为10kHz且占空比小于0.3,则该器件工作在热安全区.文中还给出了功率器件热安全工作区的判据.更多还原

【Abstract】 The phenomenon of slow thermal runaway is studied and verified with thermal circuits to describe the rise and fall characteristics of lattice temperature during continuous pulses of applied electric power which produces thermal effects.Our results show that a high-frequency switch can operate in the thermally safe operation area if the delay time of the applied pulses is longer than the thermal delay time during the fall process of lattice temperature.We show that LDMOS will switch in the thermally safe operation area with its thermal resistance of 3.5K/W and thermal capacitance of 5μs·W/K if the frequency of the applied pulses is less than 7.14kHz with a duty cycle of 0.5,or if the duty cycle of the applied pulses is less than 0.3 with a frequency of 10kHz.A criterion is given for power devices in the thermally safe operation area.更多还原