Resistorless Current Detection Circuit for Wide-Range Power Management
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Solution Overview
Problem
Conventional current detection systems in power management systems utilize resistors that cause circuit loss and reduce efficiency, and struggle with maintaining detection accuracy for small currents, especially in wide voltage ranges.
Innovation Solution
Implementing current sampling units, operational amplifiers, and a signal combiner to sample and combine terminal currents, along with a chopper amplifier and clock signal generator to regulate current magnitudes without resistors, enhancing detection accuracy and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If resistors are used for current detection, then current detection can be achieved, but circuit loss increases and efficiency decreases
Solution Approach 1:
The patent extracts and removes the resistor component from the current detection system. Instead of using a resistor to sense current through voltage drop, the invention uses a current sampling unit that directly samples the terminal current without requiring a series resistor, thereby eliminating the energy loss associated with resistive detection.
Solution Approach 2:
The patent replaces the passive resistive detection mechanism with an active electronic current sampling mechanism. The current sampling unit uses transistors and operational amplifiers to actively measure and replicate the terminal current, substituting the simple ohmic detection with a more sophisticated electronic sensing approach that does not dissipate power.
2Measurement precision
If conventional current detection systems are used, then current regulation can be achieved, but detection accuracy for small currents deteriorates in wide voltage ranges
Solution Approach 1:
The patent introduces dynamic adaptation through the operational amplifier and chopper amplifier stages. These components dynamically adjust their operation based on the input signal level and voltage conditions, enabling the system to maintain high detection accuracy for small currents while adapting to wide voltage ranges. The chopper amplifier specifically uses switching action to maintain linearity and accuracy across varying operating conditions.
Solution Approach 2:
The patent changes the operating parameters of the detection system by using multiple amplification stages with different gain characteristics. The operational amplifier provides initial amplification, and the chopper amplifier provides further conditioning, allowing the system to optimize detection sensitivity for small currents while maintaining stability across wide voltage ranges through parameter adjustment in each stage.
Data Source
AI summary
System and method for detecting one or more currents. For example, a system for detecting one or more currents includes: one or more current sampling units coupled to one or more terminal transistors respectively and configured to sample one or more terminal currents that flow between a system terminal of a power management system and one or more port terminals through the one or more terminal transistors respectively; one or more operational amplifiers coupled to the one or more current sampling units respectively and configured to generate one or more detection currents respectively, the one or more detection currents representing one or more magnitudes of the one or more terminal currents respectively; and a signal combiner configured to receive the one or more detection currents, generate a combined detection voltage representing a sum of the one or more magnitudes of the one or more terminal currents.