Voltage Detection IC Level Shifting for Isolator-Free Battery BMS
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Solution Overview
Problem
The use of isolators in battery management systems for high voltage batteries increases costs due to differences in DC levels between voltage measurement ICs, necessitating their use for communication.
Innovation Solution
A battery management system incorporating voltage detection integrated circuits with level shifters and daisy chain communication interfaces, allowing communication between ICs without the need for isolators by level-shifting operation voltages, thereby minimizing isolator usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If isolators are used for communication between voltage measurement ICs with different DC levels, then communication reliability is improved, but system cost increases
Solution Approach 1:
The patent changes the voltage level parameter by introducing a level shifter that converts voltage levels between different domains. This allows ICs operating at different DC levels to communicate without requiring isolators, thereby reducing cost while maintaining communication reliability. The level shifter dynamically adjusts voltage parameters to bridge the gap between different voltage domains.
Solution Approach 2:
The patent introduces a level shifter as an intermediary component between voltage measurement ICs with different DC levels. This intermediary device facilitates communication by translating voltage levels, eliminating the need for expensive isolators while ensuring reliable data transmission between ICs operating at different voltage domains.
2Reliability
If isolators are used for communication between voltage measurement ICs, then DC level isolation is achieved, but device complexity increases
Solution Approach 1:
The patent transforms the isolation problem from a physical separation requirement to a voltage level translation problem. By using a level shifter that dynamically adjusts voltage parameters, the system achieves DC level isolation functionality without the complexity of multiple isolators, reducing both component count and system complexity.
Solution Approach 2:
The level shifter serves as an intermediary that provides DC level isolation functionality in a more integrated and less complex manner than traditional isolators. This single intermediary component replaces multiple isolators, achieving the same isolation effect while reducing overall device complexity and component count.
3Reliability
If multiple isolators are used in the battery management system, then communication between different voltage domains is reliable, but unit price increases
Solution Approach 1:
The patent addresses the unit price increase by changing the approach from physical isolation to voltage parameter translation. The level shifter modifies voltage parameters to enable communication between different voltage domains, eliminating the need for multiple expensive isolators and thereby reducing the overall unit price of the battery management system.
Solution Approach 2:
By introducing a level shifter as an intermediary device, the patent achieves reliable communication between different voltage domains without requiring multiple isolators. This intermediary solution reduces the bill of materials cost and lowers the unit price while maintaining communication reliability across voltage domains.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces the number of isolators required, lowering the overall cost of the battery management system while maintaining effective communication and voltage detection capabilities.
Implementation Method 1
level shifters and daisy chain communication interfaces, allowing communication between ICs without the need for isolators by level-shifting operation voltages
Data Source
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AI summary
A battery management system may include: a plurality of voltage detection integrated circuits; and a battery controller configured to control charge and discharge of a high voltage battery based on a cell voltage detection result received from the voltage detection integrated circuits, and each of the detection integrated circuits includes: a cell voltage detection circuit configured to detect a voltage of at least one corresponding cell among a plurality of cells constituting the high voltage battery; first and second interfaces configured to communicate between different voltage detection integrated circuits in the detection integrated circuits; a plurality of first terminals connected with a first power source which supplies an operation voltage of the cell voltage detection circuit and the first interface; a plurality of second terminals configured to receive an operation voltage of a different voltage detection integrated circuit connected therewith through the second interface; and a level shifter configured to level-shift a voltage supplied from the first power source based on the operation voltage inputted through the second terminals to supply the level-shifted voltage as an operation voltage of the second interface.