Sense Resistor Short-Circuit Detection in Power Switch Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Sense resistor short-circuits in power supplies can lead to abnormal operation due to the lack of sense voltage, which existing technologies fail to detect effectively, resulting in potential damage or inefficiency.
Innovation Solution
A sense resistor short-circuit determiner is developed, comprising an input voltage detector, a sense voltage comparator, a blanking period setting unit, and logic gates to detect short-circuits by comparing sense voltage with a reference voltage during specific periods, including a blanking period and a short-circuited resistor detection period, using an auxiliary wire for voltage sensing and signal generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a sense resistor is used to sense switch current, then current sensing capability is improved, but the system becomes vulnerable to short-circuit faults that cause abnormal operation
Solution Approach 1:
The patent implements a feedback mechanism where the determiner continuously monitors the sense voltage and compares it with a reference voltage to detect short-circuit conditions. The comparison result feeds back to control the power switch, enabling the system to self-diagnose and respond to faults, thereby maintaining reliability while preserving sensing capability
Solution Approach 2:
The patent introduces a determiner circuit as an intermediary component between the sense resistor and the control system. This intermediary monitors the sense voltage and generates determination signals to detect short-circuits, allowing the system to identify faults without directly interfering with the primary current sensing function
2Device complexity
If existing detection methods are used, then system simplicity is maintained, but short-circuit detection capability is insufficient
Solution Approach 1:
The patent employs preliminary action by setting a blanking period before actual short-circuit detection begins. During this blanking period, the determiner prepares the detection circuit and establishes reference conditions, ensuring that detection starts only when the system is ready, which improves detection accuracy without significantly increasing overall complexity
Solution Approach 2:
The detection process is segmented into distinct phases: a blanking period for preparation and a detection period for actual measurement. This segmentation allows the system to perform complex detection operations in organized stages, managing complexity while improving detection precision
3Reliability
If detection is performed continuously, then detection reliability is improved, but power consumption and processing load increase
Solution Approach 1:
The patent implements periodic action by performing short-circuit detection only during specific detection periods rather than continuously. The determiner activates the detection function at predetermined intervals or under specific conditions, maintaining detection reliability while significantly reducing power consumption and processing load during non-detection periods
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables accurate detection of sense resistor short-circuits, preventing abnormal power supply operation by controlling the power switch and ensuring reliable voltage regulation.
Implementation Method 1
an input voltage detector detecting an input voltage and generating an input sense voltage
Implementation Method 2
a sense voltage comparator generating a comparison signal according to a result of comparison between a sense voltage and a reference voltage
Data Source
AI summary
According to the exemplary embodiments, a short-circuit of a sense resistor is detected according to a result of comparison between a sense voltage and a reference voltage at a time based on at least one of a period set based on an input sense voltage and a turn-on time of a power switch. A blanking period is set based on the input sense voltage in a current mode, and a short-circuited resistor detection period is set based on the input sense voltage.