Bidirectional Charging Circuit With Dual Gate Drives for Low On-Resistance
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Solution Overview
Problem
Existing charging circuits with silicon-based MOS transistors have high on impedance, leading to heating and reduced efficiency during bidirectional charging, and occupy a large area, complicating board layout.
Innovation Solution
A charging circuit with a switch circuit, voltage divider circuit, and gate driver is implemented, using different drive voltages for switching transistors to reduce on impedance and improve efficiency, incorporating a Bi-GaN HEMT for one transistor to minimize heat and space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a single charging cable is used to charge multiple electronic devices with different power requirements, then charging convenience is improved, but charging safety and reliability deteriorate due to inability to provide appropriate current for each device
Solution Approach 1:
The charging cable is divided into multiple independent charging units, each capable of independently controlling current output for a specific electronic device. This segmentation allows each unit to provide customized charging parameters while maintaining overall system integration, thus resolving the contradiction between charging convenience and safety.
Solution Approach 2:
The charging cable dynamically adjusts the number of active charging units and their respective current outputs based on the connected electronic devices' power requirements. This dynamic adaptation enables the cable to optimize charging safety for each device while maintaining operational convenience through automatic detection and configuration.
2Reliability
If multiple charging cables are used to charge multiple electronic devices simultaneously, then charging safety is improved, but device complexity and portability deteriorate
Solution Approach 1:
Multiple independent charging units are integrated into a single unified charging cable structure. This merging allows the cable to provide multiple independent charging channels while maintaining a single physical entity, thus improving charging safety through dedicated current control for each device while avoiding the complexity of managing multiple separate cables.
3Productivity
If a charging cable provides high current for fast charging, then charging speed is improved, but heat generation increases causing safety issues
Solution Approach 1:
The charging cable segments high current output across multiple independent charging units, each handling a portion of the total power delivery. This segmentation distributes heat generation across multiple smaller components rather than concentrating it in a single high-current path, thereby maintaining fast charging capability while reducing thermal risks.
Solution Approach 2:
The charging cable incorporates current detection and control units that act as intermediaries between the power source and electronic devices. These intermediaries monitor and regulate current flow in real-time, enabling fast charging while preventing excessive heat generation through active thermal management and current optimization.
Data Source
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AI summary
This application discloses a charging circuit, an electronic device, and a charging system, and relates to the field of electronic circuit technologies, to resolve a problem of low efficiency of the charging circuit. Specific solutions are a switch circuit, a voltage divider circuit, and a gate driver. The switch circuit is separately connected to the voltage divider circuit and the gate driver, and the voltage divider circuit is connected to the gate driver. The switch circuit is configured to: receive a power supply voltage, a first drive voltage, and a second drive voltage, and output a reference voltage and an output voltage of the charging circuit. The voltage divider circuit is configured to: receive the second drive voltage and the reference voltage, and output the first drive voltage. The gate driver is configured to: receive the reference voltage, and output the second drive voltage, where a voltage value of the second drive voltage is different from a voltage value of the first drive voltage. When there are different types of switching transistors in the switch circuit, two different drive voltages adapted to the switching transistors may be used, to reduce on impedance of the charging circuit and improve bidirectional charging efficiency of the charging circuit.