Patent ID: 6888469
Filing Date: 2005-05-03
Classification: G01K

Abstract:
1. An apparatus for estimating a semiconductor junction temperature of a corresponding semiconductor device coupled to an output node to provide an output current, the apparatus comprising: a current sensor coupled to the output node, the current sensor operative to sense said output current and to provide an output current signal indicative of the magnitude and polarity of said output current; a processor coupled to the output of the current sensor to receive the output current signal therefrom and operative to provide a temperature signal that is a function of the output current signal, wherein the temperature signal is an estimate of the semiconductor junction temperature in the semiconductor device; and an output module coupled to the processor and receiving the temperature signal therefrom and operative to compare the temperature signal to a predetermined constant, and in the event that the temperature signal exceeds the predetermined constant, providing an output alarm signal indicative that the semiconductor junction is overheating in the semiconductor device, wherein the processor includes: a current-to-power converter coupled to an absolute value module and operative to provide a value of the power dissipated in the semiconductor junction of the semiconductor device as a function of the magnitude of the output current signal; a low pass filter coupled to the current-to-power converter and receiving the value of the power dissipated in the semiconductor junction in the semiconductor device as an input and operative to filter the received value and to provide as an output a filtered power value; and a power-to-temperature converter coupled to the low pass filter and receiving the filtered power value, the power-to-temperature converter operative to provide a value of the temperature of the semiconductor junction in the semiconductor device as a function of the filtered power value.