Booster Circuit PFM Threshold Switching for Stable Low-Load Output
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Solution Overview
Problem
Existing switching power supplies face challenges in maintaining stable output voltage when the output load decreases, leading to inefficiencies in power modulation and potential instability.
Innovation Solution
The implementation of a pulse frequency modulation (PFM) mode in conjunction with a booster circuit, which determines a PFM threshold level using electronic circuits rather than digitized voltages, allowing for efficient power management across varying load conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If PWM arrangement is used to accommodate varying output current, then power supply can drive different circuits and operate at different conditions, but when output load decreases beyond a predetermined threshold, the PWM arrangement may not work in a desired manner and the pulses may not become narrower
Solution Approach 1:
The patent implements dynamic switching between PWM and PFM modes based on load conditions. The power supply transitions from pulse width modulation to pulse frequency modulation when load decreases below a threshold, allowing the system to adapt its modulation strategy dynamically to maintain reliable operation across all load ranges
Solution Approach 2:
The patent changes the modulation parameter from pulse width (PWM) to pulse frequency (PFM) based on load conditions. By switching the control parameter according to the output load level, the system maintains effective power delivery and stable operation across varying load conditions that would otherwise cause PWM to fail
2Productivity
If PWM arrangement is used, then power supply can adjust output current, but power management becomes inefficient in low-load conditions
Solution Approach 1:
The patent switches from PWM to PFM mode in low-load conditions, changing the modulation parameter to optimize power management efficiency. PFM allows for better energy utilization at low loads by adjusting pulse frequency rather than width, reducing energy losses while maintaining the ability to adjust output current
3Extent of automation
If digitized voltages are used to determine PFM threshold level, then calculation can be performed, but stability and precision may be compromised
Solution Approach 1:
The patent introduces an intermediary voltage signal that is proportional to the output voltage and used to determine the PFM threshold level. This intermediary signal provides a stable reference for threshold determination without relying solely on digitized voltage measurements, improving precision while maintaining automatic operation
Solution Approach 2:
The patent implements feedback mechanisms to monitor output voltage and adjust the PFM threshold level accordingly. By continuously monitoring and adjusting the threshold based on actual operating conditions, the system maintains high precision in threshold determination while operating automatically
Data Source
AI summary
A system includes a voltage booster circuit to receive an input voltage and provide an output voltage. A first device that is coupled to the voltage booster circuit to receive a digitized input voltage and a digitized output voltage and to determine, based on the digitized input voltage and the digitized output voltage, a first threshold level for the voltage booster circuit to operate in a pulse frequency modulation (PFM) mode. A second device that is coupled to the voltage booster circuit to receive the input voltage and the output voltage and to determine a second threshold level for the voltage booster circuit to operate in the PFM mode. A selector device that is coupled to the first device and the second device to select one of the first threshold level or the second threshold level for the voltage booster circuit.