Battery Pack Current Sensing Layout for Accuracy in Less PCB Area
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Solution Overview
Problem
Current detection circuits for battery packs face challenges in spatial utilization and accuracy due to the need for both shunt resistors and hall effect sensors, leading to potential errors and increased space requirements.
Innovation Solution
A current detection circuit design where a shunt resistor and a hall effect sensor are disposed on opposite surfaces of an insulating substrate, with the shunt resistor on one surface and the hall effect sensor on the other, along with strategically placed busbars and switching devices, to enhance spatial efficiency and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If both shunt resistor and hall device are used for current detection, then measurement precision is improved, but area of stationary object increases
Solution Approach 1:
The patent combines the shunt resistor and hall device into a single integrated current detection circuit. The shunt resistor is positioned on one surface of the circuit board while the hall device is positioned on the opposite surface, allowing both components to work together in close proximity without requiring separate discrete mounting areas. This merging approach maintains the dual-method detection accuracy while significantly reducing the total space occupied compared to using separate detection circuits.
Solution Approach 2:
The patent utilizes the third dimension (vertical spacing between circuit board surfaces) to accommodate both the shunt resistor and hall device. By placing the shunt resistor on the first surface and the hall device on the second surface of the circuit board, the design transforms a two-dimensional layout problem into a three-dimensional solution, effectively reducing the planar area requirement while maintaining both detection methods.
2Area of stationary object
If shunt resistor is used alone for current detection, then area of stationary object is reduced, but measurement precision deteriorates
Solution Approach 1:
The hall device acts as an intermediary component that detects the magnetic field generated by current flow through the shunt resistor. This indirect measurement approach allows the system to maintain high measurement precision by combining the low-side current sensing capability of the shunt resistor with the magnetic field detection capability of the hall device, achieving accurate current detection without requiring large discrete component areas.
3Area of stationary object
If hall device is used alone for current detection, then area of stationary object is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent merges the advantages of both detection methods by integrating the shunt resistor and hall device into a single circuit board structure. The shunt resistor provides direct voltage proportional to current, while the hall device provides magnetic field-based current measurement. Their combination in close proximity enables cross-validation and enhanced measurement precision that neither component could achieve alone, while occupying minimal board area through the vertical stacking arrangement.
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 configuration improves spatial utilization and reliability in detecting charging/discharging currents, reducing errors and allowing for more efficient use of space within the battery management system.
Implementation Method 1
a hall device (also known as a hall effect sensor)
Data Source
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AI summary
Provided is a current detection circuit, a battery management system and a battery pack. The current detection circuit according to an embodiment of the present disclosure is provided to detect an electric current of the battery pack. The current detection circuit includes an insulating substrate, a first busbar and a second busbar disposed on a first surface of the insulating substrate, a shunt resistor disposed between the first busbar and the second busbar on the first surface, and electrically connected to the first busbar and the second busbar, and a hall effect sensor disposed on a second surface of the insulating substrate, wherein the second surface is opposite the first surface.