Synchronous Rectifier Circuit Self-Adjusting Control Signals

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Solution Overview

Problem

Traditional rectifier circuits with diodes have low power efficiency due to significant losses, and synchronous rectifier circuits with switches face delays in control signals, especially in high-frequency AC power applications, leading to increased power losses.

Innovation Solution

A synchronous rectifier circuit with a full-bridge configuration using switching control circuits to generate control signals for switches, which self-adjust to approximate ideal operating points, reducing delays and power losses by compensating for the delay in the control signal processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If synchronous rectifier circuits use switches instead of diodes, then power efficiency is improved, but control signal delays increase power losses

Engineering Contradiction:

Improvepower lossesVSAvoidcontrol signal delays

Core Design Contradiction:

Loss of energyVSLoss of time

Solution Approach 1:

The control circuit predicts the ideal switching moments based on the AC input voltage waveform and generates control signals in advance, compensating for processing delays. This preliminary action ensures switches turn on and off at optimal times, reducing both power losses and the impact of control signal delays.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control circuit continuously monitors the AC input voltage and adjusts the control signals to maintain optimal switching timing. By using feedback from the voltage waveform, the system compensates for delays dynamically, ensuring switches operate at ideal points despite processing time requirements.

Inventive Principle:

Principle #23Feedback

2Loss of energy

If control signals are processed quickly, then switching losses are reduced, but control precision decreases

Engineering Contradiction:

Improveswitching lossesVSAvoidswitching timing precision

Core Design Contradiction:

Loss of energyVSMeasurement precision

Solution Approach 1:

The control circuit calculates ideal switching points based on voltage threshold comparisons before actual switching occurs. This preliminary determination of switching timing allows the system to prepare control signals with sufficient precision while maintaining quick response, resolving the contradiction between speed and accuracy.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS10110143B2Synchronous rectifier circuit and control method thereof

Publication Date: 2018.10.23 NANJING SILERGY SEMICONDUCTOR (HONG KONG) TECHNOLOGY LIMITED

AI summary

A synchronous rectifier circuit can include: a full-bridge rectifier circuit having first, second, third, and fourth switches, where a common node of the first and fourth switches is configured as a first input terminal of the synchronous rectifier circuit, and a common node of the second and third switches is configured as a second input terminal of the synchronous rectifier circuit; a switching control circuit configured to generate a first control signal to control the first and third switches, and a second control signal to control the second and fourth switches; and the switching control circuit being configured to self-adjust the first and second control signals to control operating points of the first, second, third, and fourth switches to be approximately ideal operating points.