Power Supply Controller Ramp Signal Offset for Fast Mode Transition
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Solution Overview
Problem
Existing power supply controllers for battery charging and load power supply take a long time to transition between charging and supplying current, leading to delays and potential battery damage from large discharge currents due to repeated toggling.
Innovation Solution
A power supply controller with a switching control circuit that uses error signals and a ramp signal to adjust the duty cycle of switching control signals, allowing rapid switching between charging and supplying modes by offsetting the DC value of the ramp signal based on adapter current thresholds, minimizing toggling and reducing transition time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If conventional power supply controllers are used to transition between charging and supplying current, then the controller can perform basic battery charging and load power supply functions, but the transition time is long and toggling occurs repeatedly
Solution Approach 1:
The patent applies preliminary action by pre-charging the output capacitor before switching modes. When transitioning from battery charging to load power supply, the controller first activates a pre-charge switch to charge the output capacitor through a pre-charge resistor, preparing the output voltage in advance. This preliminary charging action reduces the inrush current and voltage spike that would otherwise occur during mode transition, thereby reducing transition time and preventing battery damage from large discharge currents.
2Loss of time
If the power supply controller switches modes rapidly, then transition time is reduced, but control precision and stability may be compromised
Solution Approach 1:
The patent applies preliminary action by pre-charging the output capacitor before switching modes. When transitioning from battery charging to load power supply, the controller first activates a pre-charge switch to charge the output capacitor through a pre-charge resistor, preparing the output voltage in advance. This preliminary charging action reduces the inrush current and voltage spike that would otherwise occur during mode transition, thereby reducing transition time and preventing battery damage from large discharge currents.
Solution Approach 2:
The patent uses the output capacitor as an intermediary energy storage element during mode transitions. The capacitor acts as a buffer that can quickly supply or absorb current without directly impacting the battery or load. By introducing this intermediary component, the system achieves rapid mode switching while maintaining control precision, as the capacitor's voltage cannot change instantaneously, providing natural smoothing of transitions.
Data Source
AI summary
In one embodiment, a power supply controller may be formed including configuring the power supply controller to use an error signal and a ramp signal to control a duty cycle of a switching control signal that is configured to control first and second switches to charge a battery, and configuring the power supply controller to selectively offset a dc value of the ramp signal responsively to detecting the adapter current is greater than a first value wherein offsetting the dc value of the ramp signal changes the duty cycle of the switching control signal to supply current from the battery to a load.