Patent ID: 7808762
Filing Date: 2010-10-05
Classification: G05F,H01L

Abstract:
1. A semiconductor device comprising: a constant voltage circuit configured to convert an input voltage to a predetermined voltage by controlling an output transistor; and an overheat protection circuit configured to restrict output current of the constant voltage circuit in accordance with temperature of the semiconductor device, the overheat protection circuit including: a diode to detect the temperature of the semiconductor device; a resistor connected in series with the diode; a reference voltage line; and a comparator for comparing a potential at an anode of the diode to a potential on the reference voltage line, and if the potential at the anode is greater than the potential on the reference voltage line then controlling the output transistor to stay on, and if the potential at the anode is less than the potential on the reference voltage line then controlling the output transistor to turn off, wherein the comparator outputs a signal at a low level when the potential at the anode is greater than the potential on the reference voltage line and the comparator outputs a signal at a high level when the potential at the anode is less than the potential on the reference voltage line, and wherein the resistor is formed on the semiconductor device between an N+ region that is a cathode electrode of the diode and a P+ region that is connected to ground.