Sensor integrated circuits and methods for safety critical applications

A sensor integrated circuit comprising:

• a first processing channel responsive to a first analog signal to generate with a first accuracy a first processed signal, wherein the first analog signal is provided by a first type of magnetic field sensing element;
• a second processing channel responsive to a second analog signal to generate with a second accuracy a second processed signal, wherein the second accuracy is different than the first accuracy, and wherein the second analog signal is provided by a second type of magnetic field sensing element that is different than the first type of magnetic field sensing element;
• and
• a checker circuit responsive to the first processed signal and the second processed signal and configured to detect a fault in the sensor integrated circuit and generate a fault signal indicative of the fault when the first processed signal and the second processed signal differ from each other by more than a predetermined amount, wherein the checker circuit comprises a first sample circuit configured to sample the first processed signal and generate a first sampled signal, a second sample circuit configured to process the second processed signal and generate a second sampled signal, and a window comparator responsive to the first sampled signal and the second sampled signal and configured to generate the fault signal.

A sensor integrated circuit comprising:

• a first processing channel responsive to a first analog signal to generate with a first accuracy a first processed signal;
• a second processing channel responsive to a second analog signal to generate with a second accuracy a second processed signal, wherein the second accuracy is different than the first accuracy;
• a checker circuit responsive to the first processed signal and the second processed signal and configured to detect a fault in the sensor integrated circuit and generate a fault signal indicative of the fault when the first processed signal and the second processed signal differ from each other by more than a predetermined amount, wherein the checker circuit comprises a first sample circuit configured to sample the first processed signal and generate a first sampled signal, a second sample circuit configured to process the second processed signal and generate a second sampled signal, and a window comparator responsive to the first sampled signal and the second sampled signal and configured to generate the fault signal;
• at least one first magnetic field sensing element configured to sense a magnetic field and generate the first analog signal for coupling to the first processing channel;
• and
• at least one second magnetic field sensing element configured to sense the magnetic field and generate the second analog signal for coupling to the second processing channel.

A sensor integrated circuit comprising:

• a first processing channel responsive to a first analog signal to generate with a first accuracy a first processed signal;
• a second processing channel responsive to a second analog signal to generate with a second accuracy a second processed signal, wherein the second accuracy is different than the first accuracy;
• a checker circuit responsive to the first processed signal and the second processed signal and configured to detect a fault in the sensor integrated circuit and generate a fault signal indicative of the fault when the first processed signal and the second processed signal differ from each other by more than a predetermined amount, wherein the checker circuit comprises a first sample circuit configured to sample the first processed signal and generate a first sampled signal, a second sample circuit configured to process the second processed signal and generate a second sampled signal, and a window comparator responsive to the first sampled signal and the second sampled signal and configured to generate the fault signal;
• and
• wherein the sensor integrated circuit comprises an angle sensor and wherein the first processing channel comprises a zero crossing detector and the second processing channel comprises a CORDIC processor.

A sensor integrated circuit comprising:

• a first processing channel responsive to a first analog signal to generate with a first accuracy a first processed signal;
• a second processing channel responsive to a second analog signal to generate with a second accuracy a second processed signal, wherein the second accuracy is different than the first accuracy;
• a first checker circuit responsive to the first processed signal and the second processed signal and configured to detect a fault in the sensor integrated circuit and generate a fault signal indicative of the fault when the first processed signal and the second processed signal differ from each other by more than a predetermined amount, wherein the first checker circuit comprises a first sample circuit configured to sample the first processed signal and generate a first sampled signal, a second sample circuit configured to process the second processed signal and generate a second sampled signal, and a window comparator responsive to the first sampled signal and the second sampled signal and configured to generate the fault signal;
• a first semiconductor die configured to support the first processing channel, the second processing channel, and the first checker circuit;
• a third processing channel responsive to a third analog signal to generate with the first accuracy a third processed signal;
• a fourth processing channel responsive to a fourth analog signal to generate with the second accuracy a fourth processed signal;
• a second checker circuit responsive to the third processed signal and the fourth processed signal and configured to detect a fault in the sensor integrated circuit when the third processed signal and the fourth processed signal differ from each other by more than the predetermined amount;
• and
• a second semiconductor die configured to support the third processing channel, the fourth processing channel, and the second checker circuit.