Reverse Charging Current Control via SDP-to-CDP Switching
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Solution Overview
Problem
Current mobile phones with Standard Downstream Port (SDP) type data ports can only achieve a maximum reverse charging current of 500 mA, which is insufficient for rapid charging, and existing solutions do not effectively manage battery safety and longevity during reverse charging.
Innovation Solution
A reverse charging device that utilizes a CDP interface chip and a processor to establish a current transmission path, allowing for higher reverse charging currents by switching between SDP and CDP modes, and includes a control IC for overcurrent protection and a parasitic diode to manage charging currents, ensuring safe and efficient charging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If SDP port communication protocol is used for reverse charging, then device compatibility is improved, but reverse charging current is limited to 500 mA which is insufficient for rapid charging
Solution Approach 1:
The patent changes the communication protocol parameter from SDP to CDP, enabling the data line to transmit higher currents. By modifying the protocol type, the system achieves both high current capability (up to 3A) and device compatibility, as CDP is supported by modern USB devices.
2Productivity
If reverse charging is performed without current regulation, then charging speed is improved, but battery safety and longevity deteriorate due to excessive current
Solution Approach 1:
The patent implements feedback control by continuously monitoring the battery's voltage, current, and temperature parameters during reverse charging. Based on real-time battery status, the system dynamically adjusts the charging current to optimize charging speed while ensuring battery safety and longevity.
Solution Approach 2:
The patent employs dynamic current regulation that adapts the charging current based on real-time battery conditions. The system transitions from static current limiting to dynamic adjustment, allowing maximum current when battery conditions are optimal and reducing current when temperature or voltage thresholds are approached, thus balancing speed and safety.
3Productivity
If high reverse charging current is enabled, then charging efficiency is improved, but heat generation increases causing battery overheating and potential damage
Solution Approach 1:
The patent implements periodic monitoring of battery temperature and charging current. The system continuously checks temperature parameters at regular intervals and adjusts the charging current accordingly, creating a periodic control cycle that maintains high charging efficiency while preventing overheating through timely current reduction when temperature thresholds are approached.
Data Source
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AI summary
The present disclosure relates to a reverse charging device and a method and device for regulating a reverse charging current and belongs to the technical field of terminal devices. The reverse charging device includes a processor, a Standard Downstream Port (SDP) and a first link on which a Charging Downstream Port (CDP) interface chip. When it is detected that an On-The-Go (OTG) adapter is plugged into the SDP, the processor is connected with the SDP through the first link, and the processor, the CDP interface chip and the SDP form a CDP to perform reverse charging through the CDP and the OTG adapter, herein the CDP has a current transmission capability higher than the SDP. According to the present disclosure, the CDP interface chip is arranged on the first link, so that, when the OTG adapter is plugged into the SDP, the processor, the CDP interface chip and the SDP co-act to form the CDP. Since the CDP has a current transmission capability higher than the SDP, a reverse current value is higher than that output by a conventional reverse charging device.