Switch Mode Power Supply Control Circuit with Dynamic Loop Gain
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Solution Overview
Problem
Switch mode power supplies face challenges in rapidly responding to sudden changes in load conditions, leading to prolonged recovery times to steady state operation due to fixed loop gain during transient situations.
Innovation Solution
A control circuit that includes a compensation signal generating circuit, a switching signal generating circuit, a judge circuit to determine operation states, and a loop gain regulating circuit to dynamically adjust loop gain based on the operation state, allowing for increased loop bandwidth and accelerated response during dynamic changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If fixed loop gain is used during transient situations, then steady-state stability is maintained, but response speed to load changes is slow
Solution Approach 1:
The patent applies dynamics by making the loop gain adjustable rather than fixed. The control circuit dynamically changes the loop gain based on the operation state of the power supply, using a judge circuit to detect transient conditions and a gain adjustment circuit to modify the compensation signal accordingly. This resolves the contradiction by allowing the system to be static (fixed gain) during steady-state for stability, and dynamic (variable gain) during transient for fast response.
2Loss of time
If loop gain is increased during dynamic states, then response time is reduced, but steady-state performance may be affected
Solution Approach 1:
The patent uses periodic action by continuously monitoring the operation state through the judge circuit and periodically adjusting the loop gain based on detected conditions. The system switches between different gain states (high gain during transient, normal gain during steady-state) based on real-time feedback, ensuring fast recovery without compromising steady-state performance. This is achieved through the judge circuit detecting transient conditions and the gain adjustment circuit applying appropriate gain modifications only when needed.
Data Source
AI summary
In one embodiment, a control circuit configured to control a switch mode power supply, can include: (i) a compensation signal generating circuit configured to generate a compensation signal according to an error between an output voltage feedback signal and a first reference voltage of the switch mode power supply; (ii) a switching signal generating circuit configured to control a switching operation of a power switching device of the switch mode power supply according to the compensation signal; (iii) a judge circuit configured to determine an operation state of the switch mode power supply according to the output voltage feedback signal; and (iv) a loop gain regulating circuit configured to regulate a loop gain of the control circuit according to the operation state.