Boost Converter Topology for Low Battery Voltage Support
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional boost converters face inefficiencies at low input voltages, particularly when used with silicon anode batteries, and struggle to deliver sufficient current to high-density displays like those using White Light Emitting Diodes (WLEDs), leading to reduced run time and increased power consumption.
Innovation Solution
The proposed solution involves a boost converter topology that includes an inductive step converter and a switched capacitor circuit, with a voltage doubler mode that is selectively enabled or disabled based on the crossover point of the output voltage to input voltage ratio, allowing for efficient voltage boosting from low battery voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional boost operation is used at low input voltages, then the battery voltage can be boosted, but the efficiency becomes significantly lower
Solution Approach 1:
The boost converter is segmented into two distinct circuits: an inductive step converter for voltage boosting and a switched capacitor voltage doubler for high-voltage generation. This segmentation allows each circuit to operate in its optimal efficiency range, with the inductive converter handling low-voltage boosting and the capacitor circuit handling high-voltage multiplication, thereby resolving the efficiency degradation at low input voltages
Solution Approach 2:
The system dynamically switches between inductive boost mode and capacitive doubler mode based on the battery voltage level and load requirements. When battery voltage is low, the inductive converter operates; when higher voltage is needed, the capacitor circuit engages to double the voltage. This dynamic operation maintains high efficiency across the entire operating range
2Power
If conventional boost topologies are used to deliver sufficient current to high-density displays, then the display can be powered, but significantly high coil inductance and/or switching technologies are required
Solution Approach 1:
The patent merges the inductive step converter and the switched capacitor voltage doubler into a single integrated power management system. This combination allows the inductive converter to handle current delivery efficiently while the capacitor circuit provides voltage multiplication, eliminating the need for excessively high inductance values or complex switching technologies that would be required in a conventional single-stage boost topology
3Illumination intensity
If the number of WLEDs in the display is increased for higher density, then the display quality improves, but the power consumption of the boost converter becomes a significant portion of total system power
Solution Approach 1:
The system changes the operating parameters of the power conversion by using two different circuits optimized for different voltage ranges. The inductive converter operates efficiently at low voltage with high current, while the capacitor voltage doubler operates at high voltage with lower current. This parameter change allows the system to power high-density displays with more WLEDs without proportionally increasing boost converter power consumption
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the efficiency of voltage boosting, maintaining high efficiency over a wide range of input to output voltage ratios, reducing power consumption, and extending the run time of battery-powered devices, especially those with high-density displays.
Implementation Method 1
a voltage is applied across an inductor as a first switch is closed. During the application of the voltage... A second capacitor may then be charged to twice the selected output voltage
Data Source
AI summary
A method and apparatus for a boost converter topology for low battery voltage support. In the method, an input voltage is boosted by closing first through third switches and then opening a fourth switch to charge a capacitor. The first and second switches are then opened. The voltage is then doubled by closing the third and fourth switches to discharge the first capacitor into a second capacitor and charging a third capacitor. A further embodiment provides an additional method for selectively boosting an input voltage to an electronic device. The method first characterizes the efficiency of a circuit, and then determines a crossover point for a ratio of output voltage to input voltage, and then enabling or disabling a voltage boost converter based on the crossover point.