Safety system reset diagnostic by reset-driver(s)
AssigneeSemiconductor Components Industries, LLC
InventorDieter Jozef Joos
Life of this patent
Estimating the term…
Abstract
A device includes an open-drain driver, a comparator, and a digital logic circuit. The open-drain driver is operational to pull down and release a reset voltage on a reset line in response to an open drain enable signal. The comparator is operational to generate a comparison signal by comparing the reset voltage to an active threshold voltage. The digital logic circuit is operational to test a connection to the reset line. The test includes assertion of the open drain enable signal to pull down the reset voltage on the reset line, release of the open drain enable signal to float the reset voltage, and determine that the connection is one among good and failed in response to a change in the reset voltage relative to the active threshold voltage.
Claims20
A device comprising:
- an open-drain driver operational to pull down a reset voltage on a reset line and release the reset voltage in response to an open drain enable signal;
- a comparator coupled to the open-drain driver and operational to generate a comparison signal by comparing the reset voltage to an active threshold voltage;
- and
- a digital logic circuit coupled to the open-drain driver, coupled to the comparator, and operational to test a connection to the reset line, wherein the test includes:
- assertion of the open drain enable signal to command the open-drain driver to pull down the reset voltage on the reset line;
- release of the open drain enable signal to place the open-drain driver in a high-impedance condition that allows the reset voltage to float;
- and
- determine that the connection is one among good and failed in response to a change in the reset voltage relative to the active threshold voltage.
A method for failure detection in a connection to a reset line comprising:
- asserting an open drain enable signal with a digital logic circuit;
- pulling down a reset voltage on a reset line with an open-drain driver in response to the asserting of the open drain enable signal;
- releasing the open drain enable signal with the digital logic circuit;
- placing the open-drain driver in a high-impedance condition that allows the reset voltage to float in response to the releasing of the open drain enable signal;
- generating a comparison signal by comparing the reset voltage to an active threshold voltage with a comparator coupled to the open-drain driver;
- and
- determining that the connection is one among good and failed in response to a change in the reset voltage relative to an active threshold voltage, wherein the digital logic circuit is coupled to the open-drain driver and the comparator.
Dependencies are inferred from the claim text.