SEMICONDUCTOR INTEGRATED CIRCUIT

摘要

PURPOSE:To enable a circuit of this design itself not only to control a current-flow cycle but also to be protected against the damage due to the self-releasing heat by a method wherein the power consumption of an inner circuit is made to be controlled at about the upper limit of the internal temperature if a semiconductor integrated circuit depending on the output power of a thermal sensing voltage forming means. CONSTITUTION:A voltage Vpth, which is equal to a voltage V1, is constantly supplied to a base of an input transistor(TR) Q3, where the voltage V1 is outputted from a thermal sensing voltage forming means 1 at the upper limit of temperature during a burn-in so as to protect a semiconductor integrated circuit against the thermal breakage. When the internal temperature of the semiconductor integrated circuit is lower than the upper limit, the voltage Vpth is so set as to satisfy an inqulity V1>Vpth and a switching TRQ5 is controlled to be in an on-state. Thereby, a gate drive signal Vcsn is made to be at a drive level and an internal circuit is controlled to be in a usual operational state. When the internal temperature rises, a base.emitter voltage Vbe of a TiQ1 decreases gradually, so that the voltage V1 decreases. When the internal temperature exceeds the upper limit of temperature, the voltage V1 is so set as to satisfy an equality V1