Switched-Capacitor Gate Timing With Pre-Charged Pump Capacitors
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Solution Overview
Problem
Switched-capacitor power converters face inefficiencies due to the increasing number of capacitors and switches required for higher conversion gains, leading to complex gate driving circuits and power management challenges.
Innovation Solution
The implementation of a switched-capacitor power converter with synchronized gate-driving circuits that utilize charge from pump capacitors to transition switches between states, incorporating pre-charging circuits and phase generators to optimize voltage levels and reduce power loss, with dual-phase configurations reducing the need for high-voltage gate drivers and improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the number of capacitors and switches is increased to achieve higher conversion gains, then the voltage gain capability is improved, but the device complexity and power loss increase
Solution Approach 1:
The patent applies preliminary action by pre-charging pump capacitors before they are needed for gate driving. The pre-charge circuit charges pump capacitors in advance during periods when they are not immediately required for switching operations, so that when switches need to be actuated, the pump capacitors are already charged and ready to provide the necessary gate drive energy. This reduces the need for additional capacitors and complex charging circuits throughout the system.
Solution Approach 2:
The patent implements multi-functionality by using pump capacitors to serve multiple purposes: they function as energy storage elements for gate driving, as voltage transformation elements in the switched-capacitor network, and as pre-charged energy reserves. This multi-use approach eliminates the need for separate dedicated gate drive power supplies and reduces the overall component count while maintaining high conversion gain capability.
2Power
If more switches are used to achieve higher conversion gains, then the voltage transformation capability is improved, but the power loss and energy consumption increase
Solution Approach 1:
The patent reduces power loss by pre-charging pump capacitors before they are discharged to drive switches. The pre-charge circuit charges these capacitors in advance using available system voltage, so that when the pump capacitors discharge to provide gate drive energy, the energy transfer is more efficient and requires fewer switching operations. This preliminary charging action reduces the cumulative power loss that would otherwise occur through repeated charging and discharging cycles of multiple switches.
3Extent of automation
If complex gate driving circuits are implemented to control more switches, then the switching control capability is improved, but the circuit complexity and energy requirements increase
Solution Approach 1:
The patent extracts the gate driving energy requirement from the main power conversion path by using dedicated pump capacitors that are charged separately through a pre-charge circuit. These pump capacitors are then used exclusively for driving switch gates, separating the gate drive function from the power transformation function. This extraction simplifies the overall control circuitry because each switch can be driven by its associated pump capacitor without requiring complex coordinated control of multiple power stages.
Solution Approach 2:
The patent implements self-service by having pump capacitors automatically charge themselves through the pre-charge circuit during periods when they are not needed for switching. The system uses its own operating voltage to recharge the pump capacitors, eliminating the need for external gate drive power supplies or complex energy management circuits. Each pump capacitor serves itself by being recharged from the system's operational voltage.
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 gate driving in switched-capacitor power converters by reducing power loss and simplifying circuit complexity, allowing for higher conversion gains with fewer components and lower energy requirements.
Implementation Method 1
gate-driving circuits, each of which uses charge from a selected pump capacitor from a plurality of pump capacitors to operate a corresponding switch
Implementation Method 2
a pre-charging circuit configured to limit voltage across the switches from the first plurality of switches during power-up of the switched-capacitor power-converter
Implementation Method 3
a phase generator that includes phase switches, one of which is the second switch... the phase generator provides first and second phase voltages
Data Source
AI summary
In a power converter, each gate-driving circuit uses charge from a selected pump capacitor operate a corresponding switch. The switches transitions between different states, each of which corresponds to a particular interconnection of pump capacitors. During clocked operations, the first switch closes, thereby establishing a connection with the first pump capacitor. Prior to the first switch closing, the second switch closes.