Overheating detection circuit for detecting overheating of a power device

An overheating detection arrangement for detecting overheating of a power integrated circuit, including:

• a power device integrated in a semiconductor substrate;
• and
• an overheating detection circuit, including:
• a reverse biased pn junction formed in the same semiconductor substrate as said power device and having a reverse leakage current flow which is temperature dependent;
• voltage means formed in said semiconductor substrate as said power device and coupled to said pn junction for producing a voltage depending on the reverse leakage current flow;
• and
• threshold means connected for receiving the voltage and producing a signal when the voltage exceeds a threshold voltage to indicate that said power device is overheated;
• wherein said voltage means comprises a diffusion resistance layer.

An overheating detection arrangement for detecting overheating of a power integrated circuit, including:

• a power device integrated in a semiconductor substrate;
• and
• an overheating detection circuit, including:
• a reverse biased pn junction formed in the same semiconductor substrate as said power device and having a reverse leakage current flow which is temperature dependent;
• voltage means formed in said semiconductor substrate as said power device and coupled to said pn junction for producing a voltage depending on the reverse leakage current flow;
• and
• threshold means connected for receiving the voltage and producing a signal when the voltage exceeds a threshold voltage to indicate that said power device is overheated;
• wherein said voltage means comprises a polycrystalline silicon resistance layer.

An overheating detection arrangement for detecting overheating of a power integrated circuit, including:

• a power device integrated in a semiconductor substrate;
• and
• an overheating detection circuit comprising:
• first and second temperature detecting circuits, said first temperature detecting circuit having a first temperature threshold and said second temperature detecting circuit having a second temperature threshold lower than the first temperature threshold, each of said first and second temperature detecting circuits including:
• a reverse biased pn junction formed in the same semiconductor substrate as said power device and having a reverse leakage current flow which is temperature dependent;
• voltage means formed in said semiconductor substrate as said power device and coupled to said pn junction for producing a voltage depending on the reverse leakage current flow;
• and
• threshold means connected to said voltage means for receiving the voltage and producing a signal when the voltage exceeds a threshold voltage corresponding to the respective threshold temperature;
• and
• hysteresis means receiving the signals produced by the respective threshold means of said first and second temperature detecting circuits for producing an overheating signal in response to the signal from the threshold means of said first temperature detecting circuit indicating that said power device is overheated and continuing to produce the overheating signal until the signal from the threshold means of said second temperature detecting circuit is discontinued;
• wherein said semiconductor substrate includes a low impurity concentration layer on one side of each said pn junction which has an impurity concentration of not less than 5.times.10.sup.13 /cm.sup.2.

An overheating detection arrangement for detecting overheating of a power integrated circuit, including:

• a power device integrated in a semiconductor substrate;
• and
• an overheating detection circuit comprising:
• first and second temperature detecting circuits, said first temperature detecting circuit having a first temperature threshold and said second temperature detecting circuit having a second temperature threshold lower than the first temperature threshold, each of said first and second temperature detecting circuits including:
• a reverse biased pn junction formed in the same semiconductor substrate as said power device and having a reverse leakage current flow which is temperature dependent;
• voltage means formed in said semiconductor substrate as said power device and coupled to said pn junction for producing a voltage depending on the reverse leakage current flow;
• and
• threshold means connected to said voltage means for receiving the voltage and producing a signal when the voltage exceeds a threshold voltage corresponding to the respective threshold temperature;
• and
• hysteresis means receiving the signals produced by the respective threshold means of said first and second temperature detecting circuits for producing an overheating signal in response to the signal from the threshold means of said first temperature detecting circuit indicating that said power device is overheated and continuing to produce the overheating signal until the signal from the threshold means of said second temperature detecting circuit is discontinued;
• wherein each said voltage means comprises a diffusion resistance layer.

An overheating detection arrangement for detecting overheating of a power integrated circuit, including:

• a power device integrated in a semiconductor substrate;
• and
• an overheating detection circuit comprising:
• first and second temperature detecting circuits, said first temperature detecting circuit having a first temperature threshold and said second temperature detecting circuit having a second temperature threshold lower than the first temperature threshold, each of said first and second temperature detecting circuits including:
• a reverse biased pn junction formed in the same semiconductor substrate as said power device and having a reverse leakage current flow which is temperature dependent;
• voltage means formed in said semiconductor substrate as said power device and coupled to said pn junction for producing a voltage depending on the reverse leakage current flow;
• and
• threshold means connected to said voltage means for receiving the voltage and producing a signal when the voltage exceeds a threshold voltage corresponding to the respective threshold temperature;
• and
• hysteresis means receiving the signals produced by the respective threshold means of said first and second temperature detecting circuits for producing an overheating signal in response to the signal from the threshold means of said first temperature detecting circuit indicating that said power device is overheated and continuing to produce the overheating signal until the signal from the threshold means of said second temperature detecting circuit is discontinued;
• wherein each said voltage means comprises a polycrystalline silicon resistance layer.