Voltage Regulator Bypass Resistance Control for Fixed Frequency Operation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Switched-mode DC-DC converters face challenges in maintaining a fixed switching frequency and high duty cycles, leading to issues with electromagnetic interference and spurious output signals, especially when the input voltage varies, which affects the usable lifetime of batteries and the performance of radio transmitters.
Innovation Solution
A method for controlling the bypass resistance of a voltage regulator, allowing the generation of a regulated output voltage through controlled switching elements, where the bypass resistance is adjusted based on the difference between the duty cycle and the maximum duty cycle, enabling operation at high duty cycles without altering the switching frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the switching frequency is reduced to permit operation at higher duty cycles, then the maximum attainable duty cycle is increased, but the switching frequency falls which may cause electromagnetic interference and spurious output signals
Solution Approach 1:
A bypass resistance element is introduced as an intermediary component connected between the input voltage and output voltage. This bypass path allows the system to achieve high duty cycle operation without requiring frequency reduction, thereby avoiding electromagnetic interference while still permitting extended battery operation. The bypass resistance acts as a mediator that enables the converter to operate at high duty cycles with fixed switching frequency.
2Duration of action of moving object
If the duty cycle is increased to extend battery lifetime, then the usable lifetime of the battery is extended, but the switching frequency must be reduced which affects radio transmitter performance
Solution Approach 1:
The bypass resistance element serves as an intermediary that enables the system to achieve high duty cycle operation without frequency reduction. By providing an additional current path, the bypass resistance allows the converter to extend battery lifetime while maintaining the switching frequency at levels that do not interfere with radio transmitter performance.
3Adaptability or versatility
If a bypass resistance is added to enable high duty cycle operation, then the bypass resistance can be controlled to maintain fixed switching frequency, but the device complexity increases
Solution Approach 1:
The bypass resistance element is introduced as an intermediary component that enables high duty cycle operation. While this adds a physical component, the control mechanism leverages existing duty cycle detection circuitry and uses a simple integration-based control approach, thereby limiting the increase in overall device complexity while achieving the desired functionality.
Data Source
AI summary
Embodiments for at least one method and apparatus of controlling a bypass resistance of a voltage regulator are disclosed. One method includes generating a regulated output voltage based upon a switching voltage. The switching voltage is generated through controlled closing and opening of a series switch element and a shunt switch element, the series switch element and the shunt switch element being connected between voltages based on an input voltage. Control of a duty cycle of the switching voltage is provided by sensing and feeding back the regulated output voltage. The bypass resistance is controlled based on an integration of a difference between the duty cycle and a maximum duty cycle.