Charge Pump Input Current Limiter for Mode Switching
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Solution Overview
Problem
Charge pumps face issues with large inrush or sink currents when switching between output voltage modes, which can lead to system damage due to the inability of power sources to absorb these currents effectively.
Innovation Solution
A method and system that limit current flowing between the power source and the charge pump by controlling the transfer of charge during switching cycles, using various current-limiting circuitries such as variable resistors, switches, low dropout regulators, and voltage sources to manage voltage changes across capacitors, thereby regulating the average current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the charge pump switches between output voltage modes, then the power supply voltage can be adjusted to match signal levels, but large inrush or sink currents are generated that can damage the system
Solution Approach 1:
The patent applies preliminary action by detecting the current operating mode of the charge pump and predictively determining the required input current before mode switching occurs. This allows the system to prepare and limit the input current appropriately in advance of the switching event, preventing harmful inrush currents while enabling necessary voltage adjustments for different signal levels
Solution Approach 2:
The patent implements feedback by using the detected operating mode information to control the limiting of input current during mode transitions. The system continuously monitors the charge pump's state and adjusts the input current limitation dynamically based on the specific transition being made, ensuring safe operation while maintaining adaptability across different voltage modes
2Loss of energy
If the charge pump switches between output voltage modes, then different supply voltages can be generated for efficiency, but the power source cannot absorb the large switching currents
Solution Approach 1:
The patent applies preliminary action by detecting the current operating mode and predictively determining the required input current before mode switching occurs. This allows the system to prepare and limit the input current appropriately in advance of the switching event, preventing harmful inrush currents while enabling necessary voltage adjustments for different signal levels
Solution Approach 2:
The patent introduces an intermediary mechanism (current limitation circuitry) between the charge pump and the power source. This intermediary actively controls and limits the input current during mode transitions, protecting the power source from large switching currents while allowing the charge pump to efficiently switch between voltage modes
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 the risk of system damage by limiting switching currents, ensuring stable operation between modes and improving the overall efficiency of charge pumps.
Implementation Method 1
a flyback capacitor of the charge pump for storing charge
Data Source
AI summary
A system may include a charge pump configured to operate in a plurality of modes including a first mode in which the ratio of an output voltage to an input voltage of the charge pump is a first ratio and a second mode in which the ratio is a second ratio and a controller configured to limit current flowing between a power source of the charge pump to the charge pump, wherein the power source provides the input voltage, by limiting a transfer of charge between the power source and the charge pump during a switching cycle of the charge pump responsive to a change in operation between modes of the plurality of modes.