Interleaved Power Supply Phase Control Circuit
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Solution Overview
Problem
Interleaved switching power supplies face challenges in achieving constant on time control mode due to variable operation frequency, making it difficult to maintain a 180° phase difference between main power switches, which affects dynamic response and output voltage quality.
Innovation Solution
A control circuit and method that includes a feedback compensation signal generation circuit to sample output voltage, compare branch voltage signals with the feedback signal, and adjust the on time of main power switches to regulate the phase difference to 180°, ensuring consistent operation across both voltage regulation circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If variable operation frequency is used in interleaved switching power supply, then power conversion efficiency is improved, but phase difference control between main power switches becomes difficult to maintain at 180°
Solution Approach 1:
The patent implements a dynamic control mechanism where the control circuit continuously monitors the actual phase difference between first and second main power switches and adjusts the on-time of the second voltage regulation circuit in real-time. This dynamic adjustment ensures the phase difference is maintained at 180° despite variable operation frequency, resolving the contradiction between efficiency improvement and control difficulty.
Solution Approach 2:
The control circuit employs feedback control by detecting the actual phase difference between the two main power switches and using this information to adjust the on-time of the second voltage regulation circuit. This closed-loop feedback mechanism ensures accurate phase difference maintenance while allowing flexible frequency operation, thus improving efficiency without sacrificing control precision.
2Speed
If constant on time control mode is implemented, then dynamic response is improved, but operation frequency becomes variable making phase difference regulation difficult
Solution Approach 1:
The control circuit uses feedback control to detect the actual phase difference between first and second main power switches and automatically adjusts the on-time of the second voltage regulation circuit accordingly. This feedback mechanism simplifies the regulation process despite variable frequency operation, maintaining 180° phase difference while preserving fast dynamic response.
Solution Approach 2:
The patent replaces complex mechanical or manual phase difference adjustment mechanisms with an electronic control circuit that automatically regulates phase difference through feedback. This substitution reduces device complexity while maintaining precise phase control under constant on-time variable frequency operation.
3Device complexity
If phase difference is not maintained at 180°, then control simplicity is improved, but output voltage quality and ripple reduction are degraded
Solution Approach 1:
The control circuit implements feedback control to continuously monitor and maintain the 180° phase difference between main power switches. This automatic regulation ensures high output voltage quality and effective ripple reduction without requiring complex manual adjustment mechanisms, thus resolving the contradiction between control simplicity and output quality.
Solution Approach 2:
The control circuit dynamically adjusts the on-time parameter of the second voltage regulation circuit to maintain optimal 180° phase difference. By automatically changing this parameter based on detected phase difference, the system ensures high output voltage quality while keeping the control system relatively simple through automated parameter optimization.
Data Source
AI summary
In one embodiment, a control circuit configured for an interleaved switching power supply, can include: (i) a feedback compensation signal generation circuit configured to sample an output voltage of the interleaved switching power supply, and to generate a feedback compensation signal; (ii) a first switch control circuit configured to compare a first branch voltage signal that represents an inductor current of a first voltage regulation circuit against the feedback compensation signal, where when the first branch voltage signal is consistent with the feedback compensation signal, a first switch on signal is generated to control a first main power switch of the first voltage regulation circuit to be on for a predetermined time, and then off; and (iii) a second switch control circuit configured to compare a second branch voltage signal that represents an inductor current of a second voltage regulation circuit against the feedback compensation signal.