Output Voltage Sense Protection Using Current-Voltage Fault Detection
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Solution Overview
Problem
Power converters may incorrectly sense output voltage due to open or short circuits in the sense lines, leading to excessively high voltages that can damage loads like CPUs or ASICs during startup, as the controller continues to increase power flow.
Innovation Solution
A control circuit that determines a fault condition by analyzing output current and voltage signals, using software or hardware comparators to detect if current exceeds a threshold while voltage remains below a threshold, synchronizing these comparisons to identify faulty voltage sensing, and shuts down the power converter if necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the controller continues to increase power flow during startup based on low voltage sensing, then the power converter can reach its operating voltage, but if the voltage sensing is faulty (open/short circuit), this may result in excessively high output voltages that damage loads
Solution Approach 1:
The patent implements feedback by continuously monitoring both voltage and current signals and comparing them against expected relationships. The control circuit uses the current signal as a reference to verify whether the voltage signal readings are consistent with actual power converter operation, creating a closed-loop verification system that detects sensing faults without additional hardware sensors
Solution Approach 2:
The patent uses the current signal as an intermediary to indirectly verify voltage sensing accuracy. Instead of directly measuring voltage with potentially faulty sense lines, the system uses the current signal (which is reliably measured) as a mediator to infer whether the voltage reading is valid by checking if the voltage-current relationship matches expected operational characteristics
2Reliability
If additional hardware elements such as current sources, comparators, or analog circuitry are used for fault detection, then detection reliability improves, but device complexity and cost increase
Solution Approach 1:
The patent implements self-service by using the existing control circuit's processing capabilities to perform fault detection. The system uses its own existing voltage and current signal processing infrastructure to verify sensing accuracy, eliminating the need for separate dedicated fault detection hardware. The control circuit firmware itself performs the verification function that would otherwise require additional analog circuitry
Solution Approach 2:
The patent makes the control circuit multi-functional by having it perform both normal power conversion control and voltage sensing fault detection using the same hardware resources. The existing voltage and current signal acquisition paths serve dual purposes: normal operation monitoring and fault condition verification, eliminating the need for dedicated fault detection hardware
Data Source
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AI summary
A control circuit and a corresponding method is presented. The control circuit may be configured to control a power converter. The control circuit may be configured to receive a voltage signal indicative of an output voltage at an output of the power converter. The control circuit may be configured to receive a current signal indicative of an output current at the output of the power converter. The control circuit may be configured to determine a fault condition associated with the voltage signal based on the current signal and based on the voltage signal. By determining a fault condition based on an analysis of the sensed output voltage and the sensed output current, it becomes possible to detect the fault condition in a simple and efficient manner.