Synchronous Rectification Circuit With Multiplexed Single Comparator
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Solution Overview
Problem
Current synchronous rectification circuits in power supplying devices require two or more comparators to compare reference signals, leading to increased power consumption, circuit area, and potential errors due to accumulated comparator errors.
Innovation Solution
A synchronous rectification circuit using a multiplexer to alternately input a first reference signal or a second reference signal to a single comparator, which compares a detection signal of a switch to generate a comparison result signal for controlling the switch, thereby reducing power consumption and circuit area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If two or more comparators are used to compare reference signals for synchronous rectification, then the rectification control accuracy is improved, but the power consumption and circuit area increase
Solution Approach 1:
The patent merges the functions of multiple comparators into a single comparator by using a multiplexer to time-division multiplex multiple reference signals. This single comparator sequentially compares different reference signals with the detection signal, achieving the same control accuracy as multiple comparators while reducing circuit area and power consumption.
Solution Approach 2:
The patent employs periodic action through time-division multiplexing, where the multiplexer periodically switches between different reference signals (first reference signal for turn-on control, second reference signal for turn-off control) based on a control signal. This periodic switching allows a single comparator to perform multiple comparison functions sequentially, maintaining accuracy while reducing hardware complexity.
2Measurement precision
If two or more comparators are used to compare reference signals, then the rectification control accuracy is improved, but the power consumption increases
Solution Approach 1:
The patent merges the functions of multiple comparators into a single comparator by using a multiplexer to time-division multiplex multiple reference signals. This single comparator sequentially compares different reference signals with the detection signal, achieving the same control accuracy as multiple comparators while reducing circuit area and power consumption.
Solution Approach 2:
The single comparator is designed to perform multiple functions by comparing different reference signals at different time periods. It serves both as a turn-on control comparator (comparing first reference signal) and a turn-off control comparator (comparing second reference signal), making the comparator multi-functional and reducing overall power consumption.
3Ease of operation
If two different comparator circuits are used to process reference signals, then the control functions are separated, but error components accumulate and affect accuracy
Solution Approach 1:
The patent merges multiple comparator functions into a single comparator circuit, ensuring that all reference signal comparisons are performed by the same hardware. This eliminates the accumulation of error components that would occur with separate comparator circuits, as all comparisons share the same reference voltage and comparison threshold, thereby maintaining high accuracy.
Solution Approach 2:
The multiplexer acts as an intermediary that selectively connects different reference signals to the single comparator. This intermediary component enables the separation of control functions (turn-on and turn-off control) while ensuring all comparisons are made by the same comparator, preventing error accumulation and maintaining synchronization accuracy.
Data Source
AI summary
The present application provides a synchronous rectification circuit, which adopts a multiplexer that selectively inputs a first reference signal or a second reference signal to a comparator by coupling the first and second reference signal. A comparing signal is generated to a switch element by comparing a switch input signal. Hereby, the switch element is under control for synchronous rectification.