Load drive apparatus
Provided are a load drive apparatus in which a semiconductor chip using DTI for inter-element separation is mounted, the load drive apparatus being capable of diagnosing a dielectric strength voltage of the DTI and highly reliable and a failure diagnosis method of the load drive apparatus. There is provided a load drive apparatus in which a semiconductor chip is mounted. The semiconductor chip includes a load drive output unit formed on a semiconductor substrate. The load drive output unit has a first region where an MOSFET that controls load driving is formed and a second region insulated and separated by DTI from the first region and includes a first leakage current detection element provided in the first region, a second leakage current detection element provided in the second region, and a failure detection unit that determines a failure of the load drive output unit.
1. A load drive apparatus in which a semiconductor chip is mounted,
wherein the semiconductor chip includes a load drive output unit formed on a semiconductor substrate,
the load drive output unit has a first region where an MOSFET that controls load driving is formed and a second region insulated and separated by DTI from the first region, and
wherein the load drive output unit includes:
a first leakage current detection element provided in the first region;
a second leakage current detection element provided in the second region; and
a failure detection unit that determines a failure of the load drive output unit.
2. The load drive apparatus according to claim 1 ,
wherein in a case where a potential difference is provided between the first leakage current detection element and the second leakage current detection element and a current equal to or more than a predetermined value is detected, the failure detection unit determines that the load drive output unit is faulty.
3. The load drive apparatus according to claim 1 ,
wherein in a case where a current is applied between the first leakage current detection element and the second leakage current detection element and a voltage equal to or less than a predetermined value is detected, the failure detection unit determines that the load drive output unit is faulty.
4. The load drive apparatus according to claim 1 ,
wherein the semiconductor chip includes a redundant output unit of the load drive output unit,
wherein the redundant output unit includes a third region where an MOSFET that controls load driving is formed and a fourth region insulated and separated by DTI from the third region, and
wherein the redundant output unit includes:
a third leakage current detection element provided in the third region; and
a fourth leakage current detection element provided in the fourth region.
5. The load drive apparatus according to claim 4 ,
wherein in a case where the failure detection unit determines that the load drive output unit is faulty, when a potential difference is provided between the third leakage current detection element and the fourth leakage current detection element and a current equal to or less than a predetermined value is detected, a load drive function is switched from the load drive output unit to the redundant output unit.
6. The load drive apparatus according to claim 4 ,
wherein in a case where the failure detection unit determines that the load drive output unit is faulty, when a current is applied between the third leakage current detection element and the fourth leakage current detection element and a voltage equal to or more than a predetermined value is detected, the load drive function is switched from the load drive output unit to the redundant output unit.
7. The load drive apparatus according to claim 1 ,
wherein the load drive apparatus includes a redundant output unit of the load drive output unit formed on a semiconductor substrate of another semiconductor chip different from the semiconductor chip,
wherein the redundant output unit has a third region where an MOSFET that controls load driving is formed and a fourth region insulated and separated by DTI from the third region, and
wherein the redundant output unit includes:
a third leakage current detection element provided in the third region; and
a fourth leakage current detection element provided in the fourth region.
8. The load drive apparatus according to claim 7 ,
wherein in a case where the failure detection unit determines that the load drive output unit is faulty, when a potential difference is provided between the third leakage current detection element and the fourth leakage current detection element and a current equal to or less than a predetermined value is detected, the load drive function is switched from the load drive output unit to the redundant output unit.
9. The load drive apparatus according to claim 7 ,
wherein in a case where the failure detection unit determines that the load drive output unit is faulty, when a current is applied between the third leakage current detection element and the fourth leakage current detection element and a voltage equal to or more than a predetermined value is detected, the load drive function is switched from the load drive output unit to the redundant output unit.
10. The load drive apparatus according to claim 1 ,
wherein the failure detection unit determines a failure of the load drive output unit on-board.
11. The load drive apparatus according to claim 10 ,
wherein immediately after the load of the load drive apparatus is driven or before a power source is turned off, the failure detection unit performs a failure diagnosis of the load drive output unit.
12. The load drive apparatus according to claim 1 ,
wherein the semiconductor substrate is an SOI substrate.