Reversible Buck Boost Converter with Shared Current Sense Resistor
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Solution Overview
Problem
Existing auxiliary battery pack devices for portable electronic devices, such as cellular telephones, lack efficient dual-mode power conversion capabilities to seamlessly switch between charging and power supply modes, leading to suboptimal battery charging and device operation.
Innovation Solution
A dual-mode power converter that operates in both buck and boost modes, utilizing a dual-mode power converter integrated circuit, inductor, current sense resistor, and feedback control loops to regulate charging and discharging currents, ensuring efficient battery charging and device power supply regardless of AC wall power availability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single power converter circuit is used for both buck and boost modes, then device complexity is reduced, but the ability to efficiently prioritize current usage during charging and maintain stable power supply is compromised
Solution Approach 1:
The patent implements a universal power converter circuit that can operate in both buck mode (when AC power is available) and boost mode (when battery power is used) using the same hardware components. The circuit includes switches, inductors, and capacitors configured to perform both step-down and step-up conversion, eliminating the need for separate circuits and reducing overall device complexity while maintaining full functionality in both operating modes.
Solution Approach 2:
The patent employs dynamic control mechanisms that adjust the converter's operation based on real-time conditions. A controller monitors the operational mode and dynamically switches between buck and boost configurations, adjusting switch timing and duty cycles to prioritize charging current when AC power is available and to maintain stable output when operating from battery power alone, thereby ensuring reliability across varying conditions.
2Reliability
If separate power converter circuits are used for buck and boost modes, then current prioritization and power supply stability are improved, but device complexity and component count increase
Solution Approach 1:
The patent merges the buck and boost converter circuits into a single integrated power conversion system. The same inductor, switches, and control circuitry are used for both operating modes, reducing component count and simplifying the overall circuit architecture while maintaining the ability to efficiently manage current prioritization and power supply stability through dynamic control strategies.
3Device complexity
If the converter operates without mode detection and automatic switching, then device complexity is reduced, but battery charging efficiency and device operation time are compromised
Solution Approach 1:
The patent implements a feedback control system that continuously monitors the power source availability and operational mode. The controller detects whether AC power is present and automatically switches between buck and boost modes accordingly, optimizing battery charging efficiency when AC power is available and extending device operation time when running on battery power alone, all through intelligent feedback-driven control.
4Productivity
If AC wall power is always prioritized for charging, then battery charging speed is improved, but device operation time on battery power alone is reduced
Solution Approach 1:
The patent employs dynamic control that adapts the power conversion strategy based on the operational context. When AC power is available, the system operates in buck mode to enable fast charging. When AC power is disconnected, the system seamlessly transitions to boost mode, optimizing battery discharge to extend device operation time, thereby dynamically balancing charging speed and operational duration based on power availability.
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
The dual-mode power converter effectively prioritizes current usage during charging and maintains a stable power supply to devices, optimizing battery charging and extending device operation time by regulating charging and discharging currents efficiently.
Implementation Method 1
The magnitude of the charging current is detected and controlled by detecting the voltage drop across the sense resistor
Implementation Method 2
Switches within the dual-mode power converter integrated circuit, the inductor, and the sense resistor form parts of a buck converter
Data Source
AI summary
A reversible buck or boost converter is operable in a buck mode and in a boost mode. In the buck mode, the converter receives a supply voltage via an input terminal and generates a charging current that is supplied to a battery, thereby charging the battery. The supply voltage is also supplied through the converter to an output terminal. In a boost mode, the converter receives power form the battery and generates a supply current and voltage that is output onto the output terminal. The same single current sense resistor is used both to control the charging current in the buck mode and to control a constant current supplied to the output terminal in the boost mode. The output current is controlled to be constant, regardless of changes in the in the battery voltage and changes in the output voltage.