Dual-mode Voltage Regulator for Wireless Charging Heat Reduction
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Solution Overview
Problem
Existing wireless power transmission systems for portable devices face inefficiencies due to power dissipation and heat generation in low dropout amplifiers, particularly when rectifying high input voltages to lower output voltages, which is undesirable in compact devices.
Innovation Solution
A wireless power receiver system that employs a low dropout regulator during startup and transitions to a switching regulator for efficient power delivery, disabling the low dropout regulator to prevent power dissipation and heat generation, using a feedback resistance control circuit and drive circuitry to manage the voltage output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a low dropout amplifier is used to regulate voltage from rectified voltage to output voltage, then useful regulating ability is achieved, but power is dissipated as heat leading to inefficient power transfer
Solution Approach 1:
The voltage regulation function is segmented into two distinct stages: a low dropout amplifier stage for initial regulation and a switching regulator stage for efficient power delivery. This segmentation allows each component to operate in its optimal efficiency range, with the LDO handling voltage stabilization and the switching regulator handling bulk power conversion with minimal losses.
Solution Approach 2:
The system dynamically switches between two regulator configurations based on operating conditions. The low dropout amplifier operates during startup and transitions to a switching regulator for normal operation. This dynamic reconfiguration optimizes power efficiency while maintaining voltage regulation across different operational phases.
2Stability of the object's composition
If a low dropout amplifier is used to regulate voltage, then voltage stability is maintained, but heat is generated which is undesirable in compact portable devices
Solution Approach 1:
The regulation system is divided into two functional segments: the LDO amplifier that ensures voltage stability during startup, and the switching regulator that takes over for efficient power delivery with minimal heat generation. This segmentation allows voltage stability to be maintained during critical startup phases while avoiding excessive heat during sustained operation.
Solution Approach 2:
The system employs dynamic switching between regulation modes. During startup when voltage stability is critical, the LDO amplifier is active. Once the switching regulator is initialized and stable, the system transitions to the switching regulator mode, dynamically adapting to minimize heat generation while maintaining operational stability.
3Reliability
If the rectified voltage is multiple times the output voltage, then the regulator can provide useful regulating ability, but power dissipation increases significantly
Solution Approach 1:
The system dynamically adapts its regulation strategy based on the voltage ratio between rectified and output voltages. When the input voltage is significantly higher than the output voltage, the switching regulator is engaged to handle the large voltage conversion efficiently. The LDO amplifier provides regulating ability when needed but transitions out to avoid excessive power dissipation during high voltage differential conditions.
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
This approach significantly improves power efficiency and reduces heat generation by leveraging the switching regulator after startup, ensuring that internal circuits are powered with minimal power loss and temperature rise.
Implementation Method 1
a receiver 15 including a receiver coil Ls and a serial capacitance Cs forming a similar serial resonant LC network in which the time-varying electric field induces an AC current
Implementation Method 2
The receiver 15 includes a bridge rectifier 16 (comprised of the illustrated diodes D1-D4) that rectifies the AC current to produce a DC current
Data Source
AI summary
A system comprising includes a wireless power receiver generating a rectified voltage. A low dropout regulator (LDO) generates a first regulated output voltage from the rectified voltage, during a first phase. A first switch couples the first regulated output voltage to a voltage output node during the first phase. During a second phase, the LDO generates a second regulated output voltage from the rectified voltage. A switching regulator generates a third regulated output voltage during the second phase. A second switch couples the third regulated output voltage to the voltage output node during the second phase. During a third phase, the LDO is disabled, while the switching regulator continues to generate the third regulated output voltage. The first switch opens during the third phase while the second switch remains closed.