Charger Circuit Switching Capacitive Power Conversion Modes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing charger circuits face inefficiencies in both direct and switching power conversion modes, particularly in charging time and compatibility, as they require specialized cables for high charging currents and struggle to optimize power conversion efficiency and current ripple.
Innovation Solution
A charger circuit that integrates switching and capacitive power conversion modes using shared power conversion switches, allowing for high charging currents with standard USB cables by controlling loop switches and conversion switches to achieve efficient power conversion through switching and capacitive methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a standard USB cable is used for direct charging, then compatibility is maintained, but charging current is limited to 5A maximum resulting in long charging time
Solution Approach 1:
The patent segments the power conversion function into two distinct modes: direct charging mode (for compatibility) and switching power conversion mode (for fast charging). The charging circuit can selectively activate the switching power conversion circuitry only when high current is needed, while relying on direct charging through the standard cable for normal operation, thus resolving the contradiction between cable compatibility and charging speed.
Solution Approach 2:
The charger circuit is designed with multi-functionality to operate in both direct charging mode and switching power conversion mode. The same charging circuit can adaptively switch between standard USB charging (5A limit) and fast charging modes, making it universally compatible with both standard cables and fast charging requirements without needing specialized cables.
2Loss of time
If switching power conversion mode is used to increase charging current above DC input current, then charging time is reduced, but it becomes difficult to select appropriate inductor and power switches to optimize balance among charging current amount, current ripple amplitude, conduction resistance, and power conversion efficiency
Solution Approach 1:
The patent employs parameter changes by allowing the switching power conversion circuit to dynamically adjust operating parameters such as switching frequency, duty cycle, and conduction timing of power switches. This enables the circuit to optimize the balance between charging current amount, current ripple amplitude, and power conversion efficiency without requiring complex component selections, as the parameters themselves are made variable and adaptive.
Solution Approach 2:
The power conversion circuit incorporates dynamic control mechanisms where the conduction timing of power switches is continuously adjusted based on real-time operating conditions. This dynamic adaptation allows the system to automatically optimize performance parameters without requiring manual component selection, reducing design complexity while maintaining optimal charging performance across varying load conditions.
3Productivity
If high charging current is provided through switching power conversion mode, then charging time is reduced, but conduction resistance of power switches and current ripple amplitude increase affecting power conversion efficiency
Solution Approach 1:
The patent utilizes periodic switching action where power switches are turned on and off in controlled cycles. By carefully designing the switching frequency and duty cycle, the circuit achieves high average charging current while limiting peak current ripple amplitude. The periodic conduction of power switches allows energy to be transferred in controlled pulses, reducing continuous conduction losses and maintaining higher power conversion efficiency even at high charging speeds.
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 reduces charging time, maintains compatibility with standard USB cables, and lowers costs by sharing power conversion switches, while achieving optimized power conversion efficiency and current ripple management.
Implementation Method 1
an inductor connected in series with the power loop transistor, and coupled between a third node and the second node
Implementation Method 2
at least one conversion capacitor, coupled to the conversion switch circuit; wherein, in the capacitive power conversion mode, the loop switch circuit is controlled to be ON, and the conversion control circuit controls the upper switch, the lower switch and the at least one auxiliary switch, so that in plural charging conversion periods, the at least one conversion capacitor is periodically coupled between two of the following nodes: at least one voltage division node, the input power, and the ground node, so as to convert the input power to the charging power by capacitive power conversion
Data Source
AI summary
A charging circuit includes a power conversion circuit, an inductor, and at least one conversion capacitor. The power conversion circuit includes a conversion switch circuit and a conversion control circuit. The conversion switch circuit includes an upper switch, a lower switch, and at least one auxiliary switch. In a switching conversion mode, the conversion control circuit operates the conversion switch circuit to switch the inductor to plural voltage levels repetitively for converting an input power to a charging power to charge a battery by switching power conversion. In a capacitive conversion mode, the conversion control circuit operates the conversion switch circuit to switch the conversion capacitor between two of voltage division nodes periodically for converting the input power to the charging power by capacitive power conversion.