Synchronous Rectifier Control Circuit for Node Voltage Oscillation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The oscillation of voltage values at the connection node in power converters leads to fluctuating control signals, causing frequent erroneous switching operations in synchronous rectification switches, resulting in unstable output voltage.
Innovation Solution
A control circuit comprising a first logic circuit, integrating circuit, setting comparator, logic gate, and second logic circuit is used to generate a stable turn-on control signal for the synchronous rectification switch, utilizing detection signals, accumulation operations, and comparison signals to minimize oscillation effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the control signal is generated directly based on the voltage value on the connection node, then the synchronous rectification switch can respond to voltage changes, but the oscillation of voltage values causes frequent erroneous switching operations
Solution Approach 1:
The control circuit performs preliminary actions by generating setting pulses and comparison signals before the actual switching operation. The first logic circuit generates a setting pulse when the detection voltage drops to a first predetermined voltage, and the setting comparator generates a comparison signal when the detection voltage rises to a second predetermined voltage. These preliminary signals prepare the system for switching while filtering out oscillations, ensuring reliable switching operations.
Solution Approach 2:
The control circuit introduces intermediary elements between the detection voltage and the switching operation. The first logic circuit, setting comparator, and second logic circuit act as mediators that process the detection voltage through multiple stages. These intermediaries filter out voltage oscillations and generate stable control signals, preventing frequent erroneous switching while maintaining responsive control.
2Stability of the object's composition
If the control circuit uses multiple logic circuits and comparators to filter voltage oscillations, then the control signal stability improves, but the device complexity increases
Solution Approach 1:
The control circuit is segmented into distinct functional modules: a first logic circuit for generating setting pulses, a setting comparator for generating comparison signals, and a second logic circuit for generating turn-on control signals. Each module performs a specific function in the signal processing chain, making the complex control task manageable and maintainable while achieving stable control signals through systematic segmentation.
Data Source
AI summary
A control circuit for a synchronous rectification switch of a power converter is provided. The synchronous rectification switch and a transformer of the power converter are coupled to a connection node. The control circuit includes a first logic circuit, an integrating circuit, a setting comparator, a logic gate, and a second logic circuit. The first logic circuit provides a detection signal according to a detection voltage on the connection node. The integrating circuit performs an accumulation operation on the integrated voltage value based on the detection signal to generate a setting pulse. The setting comparator provides a comparison signal according to the detection voltage and a first predetermined voltage. The logic gate outputs a setting signal according to the setting pulse and the comparison signal. The second logic circuit continuously provides a turn-on control signal in response to the setting signal. The synchronous rectification switch is turned on in response to the turn-on control signal.