Switching Power Supply Current Detection via Feedback Signal Correction
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Solution Overview
Problem
Existing switching power-supply devices require additional components to detect current, increasing cost and complexity, and consume power when detecting load current, hindering miniaturization and efficiency.
Innovation Solution
A switching power-supply device with a control circuit that generates feedback signals from the power-supply output voltage, using a correction circuit to adjust signal levels and detect current differences, allowing for adaptive voltage control without external cables or connectors, reducing power consumption by lowering voltage at light loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a separate cable or connector is provided to detect current flowing to the load, then the current detection function is achieved, but the number of parts is increased and the device cannot be miniaturized
Solution Approach 1:
The patent merges the current detection function into the existing feedback signal path by using the same cable or connector that carries the feedback signal from the power-supply output to the control circuit. The control circuit detects current information by analyzing voltage drops or signal characteristics within this shared cable/connector, eliminating the need for separate detection cables or connectors.
Solution Approach 2:
The cable or connector is given multiple functions: it serves both as the feedback signal transmission path and as the current detection path. By designing the feedback signal path to carry additional current information, the same component performs dual roles, reducing the total number of parts required.
2Measurement precision
If a resistance is used to detect current based on voltage drop, then the current detection function is achieved, but the power consumption is relatively high
Solution Approach 1:
The patent uses feedback from the power-supply output voltage to detect current information. The control circuit monitors the feedback signal characteristics (such as voltage level or current) and uses this information to determine the load current state, enabling detection without inserting additional resistances that would consume power.
Solution Approach 2:
The system uses its own existing feedback signal path and voltage characteristics to perform current detection. Rather than adding external detection components, the control circuit extracts current information from the signals already present in the power-supply system, making the detection function self-service and avoiding additional power consumption.
3Power
If the voltage of the power-supply output is maintained at a high level, then the power supply capability is sufficient for heavy loads, but the power consumption is high during light load states
Solution Approach 1:
The patent implements dynamic voltage control where the control circuit adjusts the power-supply output voltage based on the detected load current state. When light load is detected, the control circuit lowers the output voltage to reduce power consumption. When heavy load is detected, the voltage is increased to provide sufficient power supply capability.
Solution Approach 2:
The control circuit changes the voltage parameter of the power-supply output based on load conditions. By detecting the load state through the feedback signal and adjusting the output voltage accordingly, the system optimizes power consumption while maintaining adequate power supply capability for different load scenarios.
Data Source
AI summary
A switching power-supply device includes a switching element; an output circuit; a feedback signal generation circuit; a control circuit that drives the switching element, based on the feedback signal, and controls the voltage of the power-supply output; a correction circuit that corrects a signal level of the feedback signal, wherein the control circuit comprises: an oscillation circuit that generates an on-trigger signal; a current detection circuit that generates a current detection signal; a difference detection circuit that generates a difference detection signal; a comparison circuit that generates an off-trigger signal, based on the current detection signal and the difference detection signal; and a first load detection circuit that controls an operation of the correction circuit, based on the current detection signal, and wherein the control circuit changes a setting voltage of the power-supply output, according to the signal level of the feedback signal.