Switched Capacitor DC-DC Converter Multi-Mode Voltage Conversion
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Solution Overview
Problem
Conventional dc-dc converters often require multiple units to handle different voltage levels for various electrical devices, leading to increased circuit area and cost, and are inefficient when input voltage deviates, as they typically have fixed conversion ratios and cannot adapt to changes in battery voltage in implantable medical devices.
Innovation Solution
A switched capacitor dc-dc converter using only two pump capacitors and three switching phases to produce multiple output voltage levels, allowing for selective configuration between different conversion modes based on input voltage or load changes, thereby maintaining stable output voltage levels across varying input conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple dc-dc converter units are used to handle different voltage levels, then the ability to provide multiple output voltage levels is improved, but the circuit area and cost increase
Solution Approach 1:
The patent implements a multi-mode dc-dc converter that can operate in different conversion modes (first mode with three switching phases, second mode with two switching phases) to provide multiple output voltage levels. This single converter unit replaces what would traditionally require multiple separate converter units, thereby reducing circuit area while maintaining the ability to provide multiple voltage levels for different electrical devices
Solution Approach 2:
The converter dynamically switches between different operating modes based on input voltage levels and load conditions. The controller selectively activates different switching phases and capacitor configurations to adapt to changing conditions, enabling the same hardware to provide different voltage conversion ratios without requiring multiple fixed-ratio converters
2Device complexity
If fixed conversion ratio converters are used, then the circuit design is simplified, but the ability to adapt to input voltage changes deteriorates
Solution Approach 1:
The converter incorporates dynamic mode switching capability where the controller can select between a first conversion mode (with three switching phases for conversion ratios of 80% and 60%) and a second conversion mode (with two switching phases for conversion ratios of 75% and 50%). This dynamic adaptation allows the converter to maintain stable output voltages despite variations in battery voltage or load conditions, while the underlying circuit topology remains relatively simple
Solution Approach 2:
The converter changes its operational parameters (number of active switching phases, capacitor connections) based on input voltage levels and load conditions. The controller monitors system conditions and adjusts the conversion mode accordingly, enabling the circuit to adapt to input voltage changes without requiring complex redesigns
3Adaptability or versatility
If multiple switching phases are used, then the conversion ratio flexibility is improved, but the switching complexity increases
Solution Approach 1:
The converter dynamically adjusts the number of active switching phases based on operating conditions. In the first conversion mode, three switching phases are activated to achieve conversion ratios of 80% and 60%. In the second conversion mode, only two switching phases are activated for conversion ratios of 75% and 50%. This dynamic phase selection reduces unnecessary switching complexity while maintaining conversion ratio flexibility when needed
Solution Approach 2:
The switching network is segmented into multiple independent switching phases that can be selectively activated. Each switching phase has dedicated switches and capacitor connections that can be independently controlled. This segmentation allows the controller to activate only the necessary phases for the current operating mode, reducing overall switching complexity while preserving flexibility
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
The solution enables efficient conversion of input voltage to multiple output voltage levels using fewer components, reducing circuit area and cost, while maintaining stable output voltages even as the input voltage decreases, without the need for multiple converters.
Implementation Method 1
a first capacitor and a second capacitor, switches configured to selectively arrange the first and second capacitors in at least three different subcircuits relative to the input node and the output node
Data Source
AI summary
The disclosure describes techniques for converting an input voltage level to two or more output voltage levels using only two pump capacitors and three switching phases. The disclosure also describes techniques for selectively controlling a dc-dc converter to operate in different conversion modes. One mode may use only two pump capacitors and three switching phases to produce output voltage levels with a first set of conversion ratios. Another mode may use two pump capacitors and two switching phases to produce output voltage levels with a second set of conversion ratios. The first mode may use three different subcircuit arrangements of the pump capacitors. The second mode may use two different subcircuit arrangements of the pump capacitors. A converter may include switches and pump capacitors that can be selectively configured to transition between two or three different subcircuits, thereby producing output voltages according to different conversion ratios on a selective basis.