Switching Converter Input Current Detection via Duty Cycle Sensing
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Solution Overview
Problem
Existing switching converters face challenges in accurately detecting input currents, leading to potential reductions in input voltage and abnormal operations due to excessive current consumption, which can affect the performance of connected loads.
Innovation Solution
A device and method for detecting input currents using a power management integrated circuit (PMIC) that includes switching converters and sensors to measure load and input currents based on duty cycles, allowing for precise detection and adjustment of input currents to maintain stable voltage levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If switching converters are used to generate supply voltages, then power efficiency is improved, but input current magnitude cannot be accurately detected leading to voltage drops
Solution Approach 1:
The patent introduces an intermediary detection mechanism that indirectly measures input current magnitude. Instead of directly sensing the input current, the system uses the relationship between duty cycle and load current to infer input current magnitude. The duty cycle serves as an intermediary parameter that correlates with input current, allowing accurate detection without direct current sensing in the input path.
Solution Approach 2:
The patent replaces direct electrical current sensing with a control signal-based detection method. By substituting physical current measurement with analysis of duty cycle control signals and load current characteristics, the system achieves accurate input current magnitude detection without requiring additional current sensing hardware in the input path.
2Power
If excessive current is consumed by switching converters, then supply voltage generation is maintained, but input voltage is reduced
Solution Approach 1:
The patent implements a feedback mechanism where the detected input current magnitude information is used to monitor and control switching converter operation. When excessive current consumption is detected (which would cause input voltage reduction), the system can adjust operating parameters or trigger protective actions to maintain stable input voltage while ensuring continuous supply voltage generation.
3Measurement precision
If current detection accuracy is improved, then voltage stability is maintained, but device complexity increases
Solution Approach 1:
The patent enables the switching converter system to self-detect input current magnitude using existing operational parameters (duty cycle and load current). The system serves itself by utilizing information already available in the control loop, eliminating the need for separate complex detection hardware. The converter's own control signals provide the necessary data for accurate input current magnitude detection.
Data Source
AI summary
A device including a first switching converter configured to generate a negative supply voltage based on an input voltage; a load current sensor configured to sense a magnitude of a load current passing through a load to which the negative supply voltage is provided; and a first input current detector configured to detect a magnitude of a first input current provided to the first switching converter based on a duty cycle of the first switching converter and the magnitude of the load current.