Differential Current Sensing Circuit With Feedback Precision
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional current detection circuits lack sufficient precision in detecting target currents, which affects the accuracy of output feedback control in LED driver integrated circuits.
Innovation Solution
The proposed current detection circuit incorporates a differential amplifier configuration with feedback current paths and a V-I converter, along with electrostatic protection diodes and an output feedback control unit, to enhance detection precision and match the output current with a predetermined target value using a fixed on-time with bottom detection method.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional current detection circuit is used, then the circuit structure is simple, but the detection precision is insufficient
Solution Approach 1:
The patent introduces feedback current paths that feed back a portion of the output current to the input端 of the differential amplifier. This feedback mechanism compensates for input offset currents and improves detection precision by dynamically adjusting the input signals based on the actual output current, thereby resolving the contradiction between enhanced measurement precision and increased device complexity.
Solution Approach 2:
The patent employs a differential amplifier as an intermediary device between the current sense terminals and the output. The differential amplifier processes the voltage signals from the sense resistors, amplifies the differential voltage, and provides a balanced output that improves detection precision while maintaining a manageable circuit structure through its inherent symmetry.
2Measurement precision
If feedback current paths are added to improve detection precision, then detection precision increases, but device complexity increases
Solution Approach 1:
The patent merges the feedback current paths with the existing differential amplifier structure, integrating the feedback functionality into the core detection circuit rather than adding completely separate components. This integration approach improves detection precision while minimizing the increase in device complexity by sharing common elements and reducing redundant components.
Data Source
AI summary
The present disclosure provides a current detection circuit having a high detection precision. The current detection circuit includes: a current output type differential amplifier; a first input resistor, configured to be connected between a first input end of the differential amplifier and a first current sense terminal; a second input resistor, configured to be connected between a second input end of the differential amplifier and a second current sense terminal; an output resistor, configured to be connected to an output end of the differential amplifier; a first feedback current path, configured to allow a first feedback current to flow between the first input end and the output end of the differential amplifier; and a second feedback current path, configured to allow a second feedback current to flow between the second current sense terminal and the output end of the differential amplifier.