Protective circuitry controls power supply enablement
AssigneeHewlett-Packard Development Company, L.P.
InventorsRobert S Wright, Nam Nguyen, Richard W Clutter
Life of this patent
Estimating the term…
Abstract
A protective circuit compares at least two different signals and asserts a control node toward respective logic states accordingly. At least one of the signals is derived from a voltage on a power rail within a computer or other device. A switching element passes or isolates an enable signal based on the logic state of the control node, enabling or preventing operation of a power supply, accordingly. Central processing units (CPUs) or other elements are protected against electrically caused damage in the event that a fault is detected by the protective circuit.
Claims12
An electronic circuit, comprising:
- voltage divider circuitry configured to derive a check signal from a voltage present at a power rail;
- pass circuitry configured to couple a source voltage to a power node, the pass circuitry configured to bias a control node toward a first state in accordance with a voltage present at the power node;
- a comparator configured to drive the control node to a second state in accordance with a comparison of the check signal with a core signal;
- and
- a switch configured to selectively couple an enable signal to an output node in accordance with a present state of the control node,
- wherein the comparator defines a first comparator and the core signal defines a first core signal, and
- wherein the electronic circuit further includes a second comparator configured to drive the control node to the second state in accordance with a comparison of the check signal with a second core signal.
A computer, comprising:
- a main board configured to assert an enable signal;
- a power supply configured to provide at least one regulated voltage to the main board in response to the enable signal;
- and
- a protective circuit configured to selectively couple the enable signal from the main board to the power supply in accordance with a comparison of a check signal with a core signal, the check signal being about half of a voltage provided on a power rail by the power supply, the core signal being slightly greater than an operating voltage provided to a central processing unit of the main board,
- wherein the protective circuit is further configured to bias a control node toward a first state in accordance with a voltage present at a power node, the enable signal being coupled to the power supply when the control node is in the first state, the enable signal being isolated from the power supply when the control node is driven into a second state distinct from the first.
A computer, comprising:
- a main board configured to assert an enable signal;
- a power supply configured to provide at least one regulated voltage to the main board in response to the enable signal;
- and
- a protective circuit configured to selectively couple the enable signal from the main board to the power supply in accordance with a comparison of a check signal with a core signal, the check signal being about half of a voltage provided on a power rail by the power supply, the core signal being slightly greater than an operating voltage provided to a central processing unit of the main board,
- wherein the protective circuit is further configured to selectively couple the enable signal to the power supply in accordance with a comparison of the check signal with a secondary signal distinct from the core signal.
Dependencies are inferred from the claim text.