Switching Power Supply Feedback Control for Overcurrent Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Chopper-type step-down switching power supplies face challenges in performing normal feedback control during initial low output voltage conditions after power-on and when output voltage is reduced by overload, leading to potential switching element damage due to abnormal feedback control.
Innovation Solution
A switching power supply configuration with a switching element connected between an input-side main terminal and ground, a converter circuit, and control circuit blocks that enable feedback control by detecting output voltage changes, ensuring the switching element is protected from overcurrent and power consumption is reduced during light-load conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the output voltage detecting control circuit block operates only after output voltage reaches a specified value, then the circuit can avoid operating under insufficient voltage conditions, but feedback control cannot be performed during initial power-on and overload conditions
Solution Approach 1:
The patent applies preliminary action by enabling the output voltage detecting control circuit block to operate before the output voltage reaches the specified value. The circuit is designed to function during initial power-on and overload conditions, performing feedback control in advance of traditional operation thresholds. This allows the switching element control circuit block to receive feedback signals even when output voltage is low, ensuring reliable feedback control throughout all operating conditions.
2Speed
If the switching element control circuit block operates without feedback control during low voltage periods, then the circuit can start operation quickly, but the switching element may be damaged due to abnormal feedback control
Solution Approach 1:
The patent implements feedback by having the output voltage detecting control circuit block continuously monitor output voltage and generate feedback current signals to the switching element control circuit block, even during initial power-on and overload conditions. This feedback mechanism allows the switching element control circuit block to adjust switching element operation based on actual output conditions, preventing abnormal feedback control and protecting the switching element from damage while maintaining quick power-on response.
Data Source
AI summary
According to the present invention, it is possible to prevent an overcurrent from passing through a switching element 1 during overcurrent protection and reduce power consumption during standby while detecting an output voltage immediately after power-on and achieving soft start control without being restricted by time.