Interleaved Power Supply Control Circuit for Variable Frequency Stability
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Solution Overview
Problem
Interleaved switching power supplies face challenges in maintaining dynamic performance and stability due to variable operation frequency, particularly when using constant on time control mode, which complicates parallel control of voltage regulators and increases current stress on power switches and inductors.
Innovation Solution
A control circuit for interleaved switching power supplies that includes a feedback compensation signal generation circuit and power switch control circuits to activate and deactivate power switches based on inductor current signals and switching periods, ensuring interleaved operation and reducing frequency-dependent issues, thereby improving dynamic performance and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If constant on time control mode is used in interleaved switching power supplies, then the control of voltage regulators becomes more complex and current stress on power switches and inductors increases, but the power supply can operate at variable frequencies
Solution Approach 1:
The patent employs feedback mechanisms where the control circuit monitors inductor current signals and switching periods to dynamically adjust power switch activation. This feedback loop enables the system to maintain stable interleaved operation at variable frequencies by continuously adapting control signals based on actual operating conditions, thereby reducing control complexity while preserving frequency adaptability.
Solution Approach 2:
The control circuit dynamically adjusts the timing and duration of power switch activation based on real-time inductor current signals and detected switching periods. This dynamic control approach allows the interleaved power supply to operate efficiently across variable frequencies without requiring complex predetermined control schedules, simplifying the overall control architecture.
2Adaptability or versatility
If constant on time control mode is used in interleaved switching power supplies, then the control of voltage regulators becomes more complex and current stress on power switches and inductors increases, but the power supply can handle variable loads
Solution Approach 1:
The patent implements periodic interleaved operation of dual voltage conversion circuits, where each circuit operates in alternating phases. By controlling the power switches to activate in a staggered periodic manner based on switching period detection, the system distributes current stress across both circuits over time, reducing peak current demands on individual power switches and inductors while maintaining ability to handle variable total loads.
Solution Approach 2:
The power supply is divided into two separate voltage conversion circuits operating in parallel with interleaved timing. This segmentation allows the total load current to be distributed across both circuits, with each circuit handling a portion of the load during its active phase. The control circuit coordinates these segmented operations to reduce current stress on individual components while maintaining overall variable load capability.
3Ease of manufacture
If conventional control circuits are used, then the design is simpler, but dynamic performance and stability deteriorate at variable frequencies
Solution Approach 1:
The control circuit incorporates self-adjusting mechanisms that automatically adapt to variable operating frequencies without requiring external recalibration or complex design parameters. By detecting switching periods and inductor current signals in real-time, the circuit self-regulates power switch activation timing and duration, maintaining stable dynamic performance across frequency variations while keeping the overall design relatively simple.
Solution Approach 2:
The control circuit dynamically changes operating parameters such as power switch activation timing and pulse width based on detected switching periods and load conditions. This parameter adaptation allows the system to maintain optimal dynamic performance and stability across variable frequencies without requiring a completely complex control architecture, achieving a balance between simplicity and reliability.
Data Source
AI summary
In one embodiment, a control circuit configured for an interleaved switching power supply having first and second voltage conversion circuits, can include: a feedback compensation signal generation circuit that generates a feedback compensation signal; a first power switch control circuit that activates a first on signal when a first voltage signal that represents an inductor current of the first voltage conversion circuit is less than the feedback compensation signal, a first power switch of the first voltage conversion circuit being turned on based on the first on signal, and turned off after a predetermined time; and a second power switch control circuit that activates a second on signal after half of a switching period from a rising edge of the first on signal, and a second power switch control signal to turn on a second power switch of the second voltage conversion circuit based on the second on signal.