Closed-Loop Inductor Current Emulation for Fast Precise Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional power converter detector circuits fail to precisely and instantly detect inductor current, necessitating further correction.
Innovation Solution
A closed-loop inductor current emulating circuit is introduced, comprising a current sensor circuit, emulation controller circuit, feedback circuit, and charging and discharging circuit, which senses currents, determines and compensates emulating signals to accurately emulate inductor current by detecting rising and falling waveform segments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional detector circuit is used to detect inductor current, then the circuit structure is simple, but the detection precision and speed are insufficient
Solution Approach 1:
The patent creates an emulating circuit that replicates the inductor current characteristics by generating a copied current signal through capacitor charging and discharging operations. This copying approach allows precise current detection without directly measuring the inductor current, thereby improving measurement precision while maintaining reasonable circuit complexity
Solution Approach 2:
The patent introduces a capacitor as an intermediary element between the inductor and the detection circuit. The capacitor stores and releases charge to emulate the inductor current waveform, serving as a mediator that translates the inductor current into a detectable signal without requiring direct high-speed measurement of the inductor current itself
2Speed
If a conventional detector circuit is used to detect inductor current, then the circuit structure is simple, but the detection speed is insufficient
Solution Approach 1:
The capacitor performs preliminary charge storage during the inductor current flow, preparing the current waveform in advance for detection. This preliminary action allows the detection circuit to read the already-prepared current signal at any moment, achieving fast detection speed without requiring high-speed real-time measurement circuitry
Solution Approach 2:
The emulating circuit creates a real-time copy of the inductor current waveform through capacitor charging and discharging, allowing instantaneous detection of the copied signal. This copying mechanism enables fast detection speed by providing an immediately available current representation without the bandwidth limitations of direct measurement
3Measurement precision
If the emulating circuit does not use feedback, then the circuit structure is simple, but the emulating precision is insufficient
Solution Approach 1:
The patent implements a feedback mechanism where the detected emulating current is compared with the actual inductor current, and the difference is used to adjust the capacitor charging/discharging parameters. This feedback loop continuously corrects the emulating waveform, significantly improving emulating precision while adding manageable circuit complexity through standard feedback components
Data Source
AI summary
A closed-loop inductor current emulating circuit is provided. An emulation controller circuit generates an emulating signal according to a current flowing through a first terminal of a low-side switch of a power converter. When the emulation controller circuit outputs the emulating signal to a charging and discharging circuit, the charging and discharging circuit outputs a charging and discharging signal to a first terminal of a capacitor according to the emulating signal. When the emulation controller circuit outputs the emulating signal to a control terminal of the capacitor to adjust a capacitance of the capacitor, the charging and discharging circuit outputs a charging and discharging signal to the first terminal of the capacitor according to one or both of an input voltage and an output voltage of the power converter.