Dynamic Charger Current Limiting via Variable Slope Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing USB chargers are incompatible with various charging protocols due to fixed current and voltage slope behaviors, which do not adapt to different maximum current limit values, leading to inefficient and potentially damaging charging operations for portable devices.
Innovation Solution
A system and method utilizing a port power switch with a configuration module to set maximum and register-based current limit values, allowing the switch to operate in constant current mode or trip based on these values, ensuring compatibility with multiple charging profiles by modifying current and voltage behavior accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed slope is used for voltage-to-current modification in constant current mode, then the port power switch operation is simplified, but compatibility with various charging protocols having different maximum current limit values is lost
Solution Approach 1:
The patent makes the voltage-to-current slope dynamic by calculating it based on the maximum current limit value and desired constant current value for each charging protocol. Instead of using a fixed slope, the system dynamically adjusts the slope parameter (equation 1: dV/dI = (V_max - V_constant) / (I_max - I_constant)) to match the specific requirements of different charging protocols, thereby achieving both simplified operation and broad compatibility.
Solution Approach 2:
The patent changes the slope parameter based on the charging protocol being used. By modifying the voltage-to-current slope parameter according to the maximum current limit value of each protocol, the system adapts its behavior to match different charging requirements while maintaining a unified control approach.
2Ease of operation
If the port power switch uses a conventional fixed slope for current limiting, then the control logic is simplified, but the charger becomes incompatible with multiple charging protocols having different current limit values
Solution Approach 1:
The patent dynamically changes the slope parameter based on the charging protocol's maximum current limit value. The control logic remains unified and simple, but the slope parameter is adjusted according to the specific protocol requirements, achieving both ease of operation and protocol compatibility.
Solution Approach 2:
The system transitions from a static fixed slope to a dynamic slope that adapts to different charging protocols. The slope is calculated in real-time based on the protocol's current limits, maintaining simple control logic while achieving broad adaptability.
3Device complexity
If the port power switch operates with a fixed maximum current limit, then the device design is simplified, but it cannot accommodate various charging protocols with different current requirements
Solution Approach 1:
The patent implements a universal charger design that can handle multiple charging protocols by dynamically adjusting the maximum current limit value. The port power switch is configured to accept different current limit values based on the detected charging protocol, allowing a single device to serve multiple functions and support various charging profiles without requiring separate hardware for each protocol.
Solution Approach 2:
The maximum current limit value is made dynamic rather than fixed. The system adjusts the current limit based on the charging protocol being used, enabling the charger to adapt to different current requirements while maintaining a simplified unified design.
Data Source
AI summary
A method and system for optimizing the behavior of a charger connected to a portable device when the portable device current exceeds the charger current limit. The system includes a configuration module configured to set a maximum current limit and a register-based current limit values. The system further includes a port power switch configured to limit the portable device current, in the event that the portable device current exceeds the maximum current limit value. The port power switch is configures to modify the portable device current to a predetermined constant current value or reset the current to zero based on the relation between the maximum current limit and the register-based current limit value.