Power Supply Circuit with Internal Protection for Voltage Abnormalities
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Solution Overview
Problem
The existing system power supply circuits face reliability issues due to voltage abnormalities, particularly when the input voltage deviates from a suitable range, leading to unstable operation and potential malfunctions in electronic devices with large voltage variations, such as in-vehicle devices, where communication failures can prevent necessary channel suspension or restoration.
Innovation Solution
A system power supply circuit with an internal protection circuit that suspends and restarts power supply channels based on predefined voltage thresholds, independent of microcomputer control, and includes a register for customizable channel control and threshold settings to ensure optimal protection and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the system power supply circuit relies on microcomputer control for voltage abnormality protection, then the control flexibility and channel management are improved, but the reliability deteriorates when communication fails or microcomputer control is unavailable
Solution Approach 1:
The protection function is segmented into two independent parts: microcomputer-controlled protection (for normal operation) and internal protection circuit (for backup). The internal protection circuit monitors voltage independently and can suspend channels without microcomputer intervention, ensuring reliability when communication fails.
Solution Approach 2:
The internal protection circuit acts as a pre-prepared backup mechanism. Before communication failure occurs, the system is designed with this redundant protection layer that automatically activates when voltage abnormalities are detected, cushioning against potential reliability issues.
2Reliability
If the internal protection circuit uses a wider voltage range threshold, then the protection coverage is improved, but the risk of unnecessary channel suspension increases
Solution Approach 1:
Different voltage thresholds are applied to different protection levels. The internal protection circuit uses a wider threshold range (VH2/VL2) for backup protection, while the microcomputer uses a narrower threshold (VH1/VL1) for normal operation. This localized differentiation allows each protection layer to function optimally for its intended purpose.
Solution Approach 2:
The internal protection circuit intentionally uses a wider voltage threshold range than the microcomputer, accepting some excessive action (potential unnecessary suspension) as a trade-off for ensuring adequate protection coverage when the microcomputer fails.
3Reliability
If multiple protection layers are implemented, then the reliability is improved, but the device complexity increases
Solution Approach 1:
The internal protection circuit is integrated within the system power supply circuit itself, merging the backup protection function into the existing structure. This reduces the need for separate external protection circuits and minimizes overall system complexity while maintaining dual-layer protection.
Solution Approach 2:
The internal protection circuit serves multiple functions: it provides backup voltage monitoring, automatic channel suspension, and operates independently of the microcomputer. This multi-functionality reduces the need for additional dedicated components, thereby limiting complexity increase.
Data Source
AI summary
A system power supply circuit receives an input voltage VIN, and supplies a power supply voltage to multiple load circuits including a microcomputer. Multiple power supply circuits support the multiple load circuits. An abnormality detection circuit generates an abnormality detection signal that is negated when the input voltage VIN is within, and asserted when it deviates from, the first voltage range, and outputs this signal to the microcomputer. The interface circuit can communicate with the microcomputer. The interface circuit receives a control signal generated by the microcomputer in response to abnormality detection signal assertion, and suspends power supply circuit operation of a channel indicated by the control signal. When the input voltage VIN deviates from a second voltage range defined to be wider than the first voltage range, an internal protection circuit suspends at least one power supply circuit of a predetermined channel.