Power Regulator Output Capacitor Switching for Lower Inrush Current
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power regulators experience significant inrush current when switching between power modes, particularly when transitioning from low-power or power-off modes to normal-power or power-on modes, which leads to inefficiencies and charge wastage.
Innovation Solution
The implementation of an electronic system with a power regulator and an output capacitance device comprising two capacitors, where one capacitor is disconnected during low-power modes to store charge, reducing inrush current when switching back to higher power modes, and a charge supplier is used to compensate for capacitor leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the power regulator switches from low-power mode to normal-power mode, then the output voltage is raised to meet load requirements, but significant inrush current occurs causing charge wastage
Solution Approach 1:
The patent applies preliminary action by disconnecting the output capacitor from the power regulator before mode switching, and reconnecting it after switching. This preliminary disconnection prevents the capacitor from discharging during the transition, eliminating the inrush current that would normally occur when the regulator raises its output voltage from low-power to normal-power mode.
Solution Approach 2:
The patent segments the output capacitor connection into two distinct phases: connected during normal operation, and disconnected during mode transitions. This segmentation is achieved through control circuitry that selectively connects or disconnects the capacitor based on the power regulator's operational state, thereby preventing inrush current while maintaining normal functionality.
2Use of energy by moving object
If the power regulator operates in low-power mode, then power consumption is reduced, but the output capacitor discharges causing voltage droop
Solution Approach 1:
The patent applies preliminary action by reconnecting the output capacitor to the power regulator immediately after the regulator exits low-power mode. This ensures that the capacitor is ready to stabilize the output voltage as soon as normal operation resumes, preventing voltage droop and maintaining reliability during the transition from low-power to normal-power mode.
Solution Approach 2:
The patent employs feedback through control circuitry that monitors the power regulator's operational state and automatically controls the connection of the output capacitor. When the regulator transitions from low-power mode, the control circuitry detects this change and reconnects the capacitor to restore output voltage stability, ensuring reliable operation.
3Quantity of substance
If a single large output capacitor is used, then charge storage capacity is sufficient to handle inrush current, but the capacitor size and cost increase
Solution Approach 1:
The patent segments the capacitor function by using a smaller output capacitor in combination with a separate charge storage capacitor. The output capacitor maintains voltage stability during normal operation, while the charge storage capacitor provides the necessary charge during mode transitions. This segmentation allows the use of smaller, more cost-effective capacitors while achieving the same overall charge storage capacity.
Solution Approach 2:
The patent introduces a charge storage capacitor as an intermediary element that mediates between the power regulator and the output capacitor during mode transitions. This intermediary capacitor absorbs the inrush current demands, allowing the main output capacitor to remain smaller while still providing sufficient charge storage capacity for system reliability.
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 configuration significantly reduces inrush current and associated charge wastage by utilizing stored charge from the isolated capacitor, minimizing the inrush charge and current when switching back to higher power modes.
Implementation Method 1
The output capacitance device has a first capacitor and a second capacitor. When the power regulator is in the first power mode, the first capacitor and the second capacitor are both coupled to the power regulator.
Implementation Method 2
the charge supplier has a current source, driven by the power voltage to compensate for leakage from the second capacitor
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An electronic system using a power regulator with reduced inrush current is shown. An output capacitance device that is coupled between the power regulator and the load has a first capacitor and a second capacitor. When the power regulator is in the first power mode, the first capacitor and the second capacitor are both coupled to the power regulator. When the power regulator is in the second power mode, which uses less power than the first power mode, the first capacitor is still coupled to the power regulator, but the second capacitor is disconnected from the power regulator and is protected from being discharged by the power regulator.