Negative-Voltage Feedback Circuit for Accurate Converter Protection
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Solution Overview
Problem
Existing power converters face complexity in providing accurate over-voltage or under-voltage protection while switching voltages, especially for negative voltage applications.
Innovation Solution
A power converter with a feedback voltage adjusting mechanism that includes a high-side switch, a low-side switch, a control circuit, an error amplifier, and a feedback circuit. The feedback circuit senses the output voltage and adjusts it to maintain a fixed ratio with the reference voltage, enabling effective over-voltage and under-voltage protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional switching control is used for negative voltage applications, then the power converter can operate, but the control complexity becomes highly complex and accurate over-voltage or under-voltage protection cannot be provided
Solution Approach 1:
The patent implements a feedback circuit that includes an operational amplifier, resistors, and a feedback modulation element. The feedback circuit senses the output voltage and feeds it back to the control circuit through the error amplifier, enabling automatic regulation of the switching control signals. This feedback mechanism provides accurate over-voltage and under-voltage protection by continuously monitoring and adjusting the output voltage based on the reference voltage comparison.
Solution Approach 2:
The error amplifier acts as an intermediary between the feedback circuit and the control circuit. It compares the feedback voltage with the reference voltage and generates error signals that modulate the switching control. This intermediary component simplifies the control complexity by handling the complex comparison and modulation functions, allowing the main control circuit to operate more simply while maintaining high protection accuracy.
2Productivity
If switching control is implemented for negative voltage, then power can be supplied to the load, but it is difficult to provide accurate over-voltage or under-voltage protection
Solution Approach 1:
The feedback circuit continuously monitors the output voltage and feeds it back through the error amplifier to the control circuit. This closed-loop feedback ensures that the output voltage remains within the desired range by automatically adjusting the switching control signals when over-voltage or under-voltage conditions are detected, thereby providing precise voltage protection while maintaining continuous power supply to the load.
Solution Approach 2:
The error amplifier is configured to detect voltage deviations from the reference voltage before they reach dangerous levels. By performing preliminary detection and adjustment, the system prevents over-voltage and under-voltage conditions from occurring, ensuring both continuous power supply and precise protection without waiting for extreme conditions to develop.
Data Source
AI summary
A power converter having a feedback voltage adjusting mechanism for a negative voltage is provided. Input terminals of an operational amplifier are respectively connected to a zero voltage and a first terminal of a first resistor. A second terminal of the first resistor is connected to a second terminal of a low-side switch. A first current source is connected to an output terminal of the operational amplifier and a first terminal of a second resistor. A second terminal of the second resistor is connected to the first terminal of the first resistor. The first current source outputs a first current according to a signal output by the operational amplifier. A second current source outputs a second current being m times the first current and is connected to a first terminal of a third resistor. A voltage of the first terminal of the third resistor is a feedback voltage.