Rectifier Control Circuit for Wireless Power Transfer

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Solution Overview

Problem

Wireless power systems face efficiency losses due to high quiescent current requirements in traditional rectifier control circuitry, particularly at high frequencies, leading to poor low-load efficiency in mobile devices, and challenges in generating precise turn-on and turn-off thresholds for synchronous rectifiers.

Innovation Solution

A rectifier control circuit that predicts switching delays and generates switch control signals to optimize the timing of switching circuits, reducing the need for high-power comparators and improving efficiency by using a low-power digital control loop and adjustable delay lines to set precise turn-on and turn-off thresholds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If traditional rectifier control circuitry is used, then power transfer can be maintained, but quiescent current consumption is high and low-load efficiency is poor

Engineering Contradiction:

Improvequiescent current consumptionVSAvoidrectification efficiency

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent changes the operating parameters of the rectifier control circuit by using a digital control loop that can dynamically adjust switching thresholds and timing. This allows the circuit to operate efficiently across different load conditions, reducing quiescent current while maintaining reliability through adaptive parameter optimization rather than fixed high-power comparator operation.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces traditional analog comparator-based control with a digital control loop. This substitution enables more precise control with lower power consumption, as digital logic can achieve the same control functions with significantly reduced quiescent current while providing programmable flexibility for optimizing rectification efficiency at various load levels.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If high-power comparators are used for precise switching control, then switching precision is improved, but power consumption increases

Engineering Contradiction:

Improveswitching threshold precisionVSAvoidcomparator power consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by stationary object

Solution Approach 1:

The patent substitutes high-power analog comparators with a digital control loop that uses digital logic elements and lookup tables to determine switching thresholds. This digital approach achieves comparable or superior precision through programmable reference values and timing control while consuming significantly less power, as digital logic operates at lower voltage and current levels.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses digital copies or representations of voltage thresholds stored in memory or lookup tables rather than requiring high-power analog comparators to continuously generate reference voltages. This allows the system to maintain precise switching control by comparing digital representations of thresholds with actual circuit states, dramatically reducing the power required for threshold generation and comparison operations.

Inventive Principle:

Principle #26Copying

3Device complexity

If fixed switching thresholds are used, then circuit simplicity is maintained, but adaptability to different load conditions is reduced

Engineering Contradiction:

Improvecontrol circuit simplicityVSAvoidload condition adaptability

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic switching thresholds through a digital control loop that can adjust threshold values based on detected load conditions. The system monitors circuit parameters and programmatically modifies switching points to optimize performance across different operating conditions, transforming a static control circuit into an adaptive system that maintains simplicity while gaining versatility through software-based control.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent creates a universal control architecture where a single digital control loop can handle multiple operating conditions and load types. By using programmable logic and lookup tables, the same circuit structure adapts to various scenarios (different power levels, load conditions, device types) without requiring separate dedicated circuits for each case, achieving multi-functionality while maintaining relative simplicity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS11159025B2Wireless communication device and power receiving unit with wireless control channel and methods for use therewith

Publication Date: 2021.10.26 AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE LTD

AI summary

Aspects of the subject disclosure may include, for example, a power receiving unit having a wireless power receiver that receives a wireless power signal from a power transmitting unit. A rectifier circuit rectifies the wireless power signal to generate a rectified power signal in response thereto for charging a battery. A first wireless radio unit exchanges control data with a second wireless radio unit of the power transmitting unit via a wireless control channel, wherein the exchange of control data facilitates establishment of the wireless control channel, establishment of a charging session between the power receiving unit and the power transmitting unit, and control of the charging session between the power receiving unit and the power transmitting unit.