Controller Protection Circuit for MOS Defect and Overvoltage Detection
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Solution Overview
Problem
Existing electrical circuits for detecting circuit defects and preventing overvoltages in regulators do not effectively address defects in the output MOS transistor or the sub-circuits, leading to potential destruction of on-chip circuits and loads, especially in automotive applications where uncontrolled shutdowns can result in undesirable behavior.
Innovation Solution
An electrical circuit that includes a power regulator and an overvoltage suppression circuit with additional transistors and comparators to detect and limit overvoltage and undervoltage events, generating binary signals for controlled shutdowns, and using a digital part to manage these signals for proper operation within the 2.7 to 3.6 volt range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional overvoltage detection circuits are used, then overvoltage events can be detected, but defects in the output MOS transistor or sub-circuits cannot be detected, leading to potential destruction of on-chip circuits and loads
Solution Approach 1:
The power regulator circuit is divided into multiple detectable segments: the output MOS transistor, sub-circuits, and voltage regulation components. Each segment can be independently monitored for defects through separate detection paths that check for short circuits and abnormal voltage conditions, enabling comprehensive defect detection without requiring a completely new circuit architecture.
Solution Approach 2:
The circuit performs preliminary defect detection by continuously monitoring voltage levels and transistor states before overvoltage events can cause damage. The detection circuit checks for MOS transistor defects and sub-circuit failures in advance, allowing the system to prepare protective actions before catastrophic failure occurs.
2Reliability
If the output MOS transistor is assumed to be defect-free, then the circuit design is simpler, but the circuit cannot protect against defects such as drain-to-source short circuits that cause uncontrolled voltage application to loads
Solution Approach 1:
An intermediate detection circuit is introduced between the power regulator and the load. This intermediary circuit monitors the voltage output and transistor states, detecting drain-to-source short circuits and other MOS transistor defects. When defects are detected, the intermediary circuit activates protection mechanisms to prevent uncontrolled voltage from reaching the load.
3Reliability
If overvoltage protection circuits are used to prevent destruction of output MOS transistor, then overvoltage events are avoided, but the circuit cannot distinguish between overvoltage events and defects, leading to uncontrolled shutdowns
Solution Approach 1:
The circuit dynamically adjusts its protection response based on the detected condition. When an overvoltage event is detected, the system evaluates whether it stems from a defect or external condition. Based on this dynamic assessment, the circuit selectively activates controlled shutdown sequences, preventing unnecessary shutdowns while ensuring protection when genuinely required.
Data Source
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AI summary
The invention relates to an electrical circuit for detecting circuit defects and/or for preventing overvoltages in controllers, which circuit comprises a power controller circuit, having a first transistor (MOSPWR), a control loop comprising an operation amplifier (OTAPWR) and a first reference voltage source (VREFI), and feedback resistors (R1, R2, R3), and an overvoltage suppression circuit, having a second transistor (MOSPROT), a control loop comprising an operation amplifier (OTAPROT) and a reference voltage source (VREF2), and feedback resistors (R4, R5, R6), wherein the power controller circuit is provided in order to provide a voltage (VDD_PWR) for the overvoltage suppression circuit and the overvoltage suppression circuit is provided in order to provide a protected voltage (VDD_PROT).