DC-DC Converter Feedback Control With Enhanced Voltage Comparison
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing DC-to-DC converters using constant ON time (COT) control technology require comparators with high gain and high bandwidth, which can be costly and complex.
Innovation Solution
A feedback control device with an enhancing circuit that adjusts the feedback voltage or reference voltage to generate an enhanced control signal for the DC-to-DC converter, reducing the need for comparators with high gain and high bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional voltage control with high gain and high bandwidth comparators is used, then control precision is improved, but device complexity and cost increase
Solution Approach 1:
The control function is segmented into two parts: a simple comparator that only needs to compare voltages, and a separate control circuit that generates the PWM signal. This segmentation allows the comparator to have lower specifications (reducing complexity and cost) while the overall control precision is maintained through the coordinated operation of the control circuit.
Solution Approach 2:
Instead of using a high-performance comparator to directly generate the control signal, the patent inverts the approach by using a simple comparator to compare feedback voltage with a sawtooth wave, and then using a control circuit to generate the PWM signal based on the comparator output. This inversion allows the use of a lower-cost comparator while achieving the same control precision.
2Speed
If high gain and high bandwidth comparators are used, then response speed is improved, but device complexity increases
Solution Approach 1:
The response function is segmented between the comparator and the control circuit. The simple comparator provides immediate voltage comparison, and the control circuit rapidly generates PWM signals in response. This segmentation achieves fast response without requiring the comparator itself to have high bandwidth, thus reducing device complexity.
Solution Approach 2:
The control circuit acts as an intermediary between the simple comparator and the power switches. It receives the comparator output and rapidly generates the PWM control signals, thereby achieving fast response speed without placing high bandwidth requirements on the comparator, thus reducing overall system complexity.
3Device complexity
If simple control structure is used, then device complexity is reduced, but control precision deteriorates
Solution Approach 1:
The patent merges the simple comparator function with a control circuit that generates PWM signals. While the comparator structure is simple, the combined system achieves precise control through the coordinated operation of the comparator and control circuit, maintaining control precision without increasing overall device complexity.
Solution Approach 2:
The patent implements a feedback control mechanism where the output voltage is sampled and fed back to the comparator. This feedback loop, combined with the PWM generation, ensures precise control of the output voltage while keeping the control structure simple and cost-effective.
Data Source
AI summary
The invention provides a feedback control device and a feedback control method thereof. The feedback control device includes an enhancing circuit and a comparator. The enhancing circuit receives a feedback voltage corresponding to an output voltage of a DC-to-DC converter. In an embodiment, the enhancing circuit generates an enhanced feedback voltage based on the feedback voltage, and the comparator uses a comparison result between a reference voltage and the enhanced feedback voltage as a control signal to a feedback control terminal of the DC-to-DC converter. In another embodiment, the enhancing circuit generates an enhanced reference voltage based on the reference voltage, and the comparator uses a comparison result between the enhanced reference voltage and the feedback voltage as the control signal. In yet another embodiment, the comparator uses a comparison result between the enhanced reference voltage and the enhanced feedback voltage as the control signal.