Methods and apparatus for a current sensor having fault detection and self test functionality
View Patent ↗Methods and apparatus for an integrated circuit having a magnetic sensing element, a fault detection module including circuitry to detect a fault condition and to self-test operation of the circuitry to detect the fault. The integrated circuit includes a fault pin to indicate the fault condition.
1. An integrated circuit, comprising:
a sensing element;
fault detection module coupled to the sensing element, the fault detection module including circuitry to detect and output a fault condition and circuitry to perform self-test operation of the circuitry to detect the fault condition; and
a fault pin to output the fault condition and to receive a self-test command,
wherein the fault condition includes a magnetic field is above a first threshold and/or below a second threshold,
wherein the self-test is terminated before completion when the magnetic field is above a flux threshold, and
wherein the self-test operation is initiated only when the magnetic field is below a certain level associated with no magnetic field present.
2. The integrated circuit according to claim 1 , wherein the sensing element comprises a magnetic sensing element.
3. The integrated circuit according to claim 2 , wherein the magnetic sensing element comprises a Hall element.
4. The integrated circuit according to claim 2 , wherein the magnetic sensing element comprises a magnetoresistance element.
5. The integrated circuit according to claim 1 , wherein the fault condition includes a current level above a threshold.
6. The integrated circuit according to claim 1 , wherein the integrated circuit comprises a linear current sensor.
7. The integrated circuit according to claim 1 , wherein the integrated circuit comprises a magnetic field sensor.
8. The integrated circuit according to claim 1 , wherein a self-test initiation signal comprises a given voltage level applied for at least a given time duration.
9. The integrated circuit according to claim 8 , wherein the given voltage level comprises about vcc/2.
10. The integrated circuit according to claim 1 , wherein the integrated circuit outputs a result of the self-test on the fault pin.
11. The integrated circuit according to claim 10 , wherein the result comprises a voltage level indicative of pass/fail for the self-test.
12. The integrated circuit according to claim 1 , wherein the fault detection module comprises a first comparator to detect a first fault condition and a second comparator to detect a second fault condition.
13. The integrated circuit according to claim 12 , wherein the first fault condition includes a current level below a first threshold, and the second fault condition includes a current level above a second threshold.
14. The integrated circuit according to claim 1 , wherein the integrated circuit comprises a package having exactly four pins.
15. The integrated circuit according to claim 1 , wherein the integrated circuit comprises a package having a thickness of less than 1.1 mm.
16. The integrated circuit according to claim 1 , wherein the fault detection module comprises a programmable window comparator.
17. The integrated circuit according to claim 1 , wherein the integrated circuit comprises a linear current sensor.
18. The integrated circuit according to claim 1 , further comprising a three-phase power system, wherein the integrated circuit is disposed in a core of an element in the three-phase power system.